CVE-2026-66822: Microsoft.NETCore.App.Runtime.linux arm Microsoft Security Advisory CVE-2026-66822 - Vulnerability

MODERATE
Advisory Identifier: GHSA-wxxw-5cvc-53j7
CVSS 5.9
CWE-201
Published
Advisory Summary

CVE-2026-66822 is a MODERATE (CVSS 5.9) microsoft security advisory cve-2026-66822 - vulnerability (CWE-201: Insertion of Sensitive Information Into Sent Data) affecting Microsoft.NETCore.App.Runtime.linux arm libraries in the NuGet ecosystem. The issue involves microsoft security advisory cve-2026-66822 - .net and visual studio information disclosure vulnerability. Remediation is available by upgrading affected packages to version 9.0.21, 11.0.0-rc.2, 10.0.13, 8.0.32.

CVE-2026-66822 at a Glance

CVE Identifier CVE-2026-66822
GHSA Identifier GHSA-wxxw-5cvc-53j7
Severity MODERATE
CVSS v3.1 Base Score 5.9
CWE Classification CWE-201: Insertion of Sensitive Information Into Sent Data
Affected Product Microsoft.NETCore.App.Runtime.linux arm
Package Ecosystem NuGet
Published Date
Last Updated

Security Impact

CVSS: 5.9

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-66822

To remediate this vulnerability, upgrade all affected Microsoft.NETCore.App.Runtime.linux arm dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Microsoft.NETCore.App.Runtime.linux-arm fixed: 9.0.21
Upgrade Microsoft.NETCore.App.Runtime.linux-arm to 9.0.21
Microsoft.NETCore.App.Runtime.linux-arm64 fixed: 9.0.21
Upgrade Microsoft.NETCore.App.Runtime.linux-arm64 to 9.0.21
Microsoft.NETCore.App.Runtime.linux-musl-arm fixed: 9.0.21
Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm to 9.0.21
Microsoft.NETCore.App.Runtime.linux-musl-arm64 fixed: 9.0.21
Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm64 to 9.0.21
Microsoft.NETCore.App.Runtime.linux-musl-x64 fixed: 9.0.21
Upgrade Microsoft.NETCore.App.Runtime.linux-musl-x64 to 9.0.21
Microsoft.NETCore.App.Runtime.linux-x64 fixed: 9.0.21
Upgrade Microsoft.NETCore.App.Runtime.linux-x64 to 9.0.21
Microsoft.NETCore.App.Runtime.osx-arm64 fixed: 9.0.21
Upgrade Microsoft.NETCore.App.Runtime.osx-arm64 to 9.0.21
Microsoft.NETCore.App.Runtime.osx-x64 fixed: 9.0.21
Upgrade Microsoft.NETCore.App.Runtime.osx-x64 to 9.0.21
Microsoft.NETCore.App.Runtime.win-arm64 fixed: 9.0.21
Upgrade Microsoft.NETCore.App.Runtime.win-arm64 to 9.0.21
Microsoft.NETCore.App.Runtime.win-x64 fixed: 9.0.21
Upgrade Microsoft.NETCore.App.Runtime.win-x64 to 9.0.21
Microsoft.NETCore.App.Runtime.win-x86 fixed: 9.0.21
Upgrade Microsoft.NETCore.App.Runtime.win-x86 to 9.0.21
Microsoft.NETCore.App.Runtime.linux-arm fixed: 11.0.0-rc.2
Upgrade Microsoft.NETCore.App.Runtime.linux-arm to 11.0.0-rc.2
Microsoft.NETCore.App.Runtime.linux-arm64 fixed: 11.0.0-rc.2
Upgrade Microsoft.NETCore.App.Runtime.linux-arm64 to 11.0.0-rc.2
Microsoft.NETCore.App.Runtime.linux-musl-arm fixed: 11.0.0-rc.2
Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm to 11.0.0-rc.2
Microsoft.NETCore.App.Runtime.linux-musl-arm64 fixed: 11.0.0-rc.2
Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm64 to 11.0.0-rc.2
Microsoft.NETCore.App.Runtime.linux-musl-x64 fixed: 11.0.0-rc.2
Upgrade Microsoft.NETCore.App.Runtime.linux-musl-x64 to 11.0.0-rc.2
Microsoft.NETCore.App.Runtime.linux-x64 fixed: 11.0.0-rc.2
Upgrade Microsoft.NETCore.App.Runtime.linux-x64 to 11.0.0-rc.2
Microsoft.NETCore.App.Runtime.osx-arm64 fixed: 11.0.0-rc.2
Upgrade Microsoft.NETCore.App.Runtime.osx-arm64 to 11.0.0-rc.2
Microsoft.NETCore.App.Runtime.osx-x64 fixed: 11.0.0-rc.2
Upgrade Microsoft.NETCore.App.Runtime.osx-x64 to 11.0.0-rc.2
Microsoft.NETCore.App.Runtime.win-arm64 fixed: 11.0.0-rc.2
Upgrade Microsoft.NETCore.App.Runtime.win-arm64 to 11.0.0-rc.2
Microsoft.NETCore.App.Runtime.win-x64 fixed: 11.0.0-rc.2
Upgrade Microsoft.NETCore.App.Runtime.win-x64 to 11.0.0-rc.2
Microsoft.NETCore.App.Runtime.win-x86 fixed: 11.0.0-rc.2
Upgrade Microsoft.NETCore.App.Runtime.win-x86 to 11.0.0-rc.2
Microsoft.NETCore.App.Runtime.linux-arm fixed: 10.0.13
Upgrade Microsoft.NETCore.App.Runtime.linux-arm to 10.0.13
Microsoft.NETCore.App.Runtime.linux-arm64 fixed: 10.0.13
Upgrade Microsoft.NETCore.App.Runtime.linux-arm64 to 10.0.13
Microsoft.NETCore.App.Runtime.linux-musl-arm fixed: 10.0.13
Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm to 10.0.13
Microsoft.NETCore.App.Runtime.linux-musl-arm64 fixed: 10.0.13
Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm64 to 10.0.13
Microsoft.NETCore.App.Runtime.linux-musl-x64 fixed: 10.0.13
Upgrade Microsoft.NETCore.App.Runtime.linux-musl-x64 to 10.0.13
Microsoft.NETCore.App.Runtime.linux-x64 fixed: 10.0.13
Upgrade Microsoft.NETCore.App.Runtime.linux-x64 to 10.0.13
Microsoft.NETCore.App.Runtime.osx-arm64 fixed: 10.0.13
Upgrade Microsoft.NETCore.App.Runtime.osx-arm64 to 10.0.13
Microsoft.NETCore.App.Runtime.osx-x64 fixed: 10.0.13
Upgrade Microsoft.NETCore.App.Runtime.osx-x64 to 10.0.13
Microsoft.NETCore.App.Runtime.win-arm64 fixed: 10.0.13
Upgrade Microsoft.NETCore.App.Runtime.win-arm64 to 10.0.13
Microsoft.NETCore.App.Runtime.win-x64 fixed: 10.0.13
Upgrade Microsoft.NETCore.App.Runtime.win-x64 to 10.0.13
Microsoft.NETCore.App.Runtime.win-x86 fixed: 10.0.13
Upgrade Microsoft.NETCore.App.Runtime.win-x86 to 10.0.13
Microsoft.NETCore.App.Runtime.linux-arm fixed: 8.0.32
Upgrade Microsoft.NETCore.App.Runtime.linux-arm to 8.0.32
Microsoft.NETCore.App.Runtime.linux-arm64 fixed: 8.0.32
Upgrade Microsoft.NETCore.App.Runtime.linux-arm64 to 8.0.32
Microsoft.NETCore.App.Runtime.linux-musl-arm fixed: 8.0.32
Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm to 8.0.32
Microsoft.NETCore.App.Runtime.linux-musl-arm64 fixed: 8.0.32
Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm64 to 8.0.32
Microsoft.NETCore.App.Runtime.linux-musl-x64 fixed: 8.0.32
Upgrade Microsoft.NETCore.App.Runtime.linux-musl-x64 to 8.0.32
Microsoft.NETCore.App.Runtime.linux-x64 fixed: 8.0.32
Upgrade Microsoft.NETCore.App.Runtime.linux-x64 to 8.0.32
Microsoft.NETCore.App.Runtime.osx-arm64 fixed: 8.0.32
Upgrade Microsoft.NETCore.App.Runtime.osx-arm64 to 8.0.32
Microsoft.NETCore.App.Runtime.osx-x64 fixed: 8.0.32
Upgrade Microsoft.NETCore.App.Runtime.osx-x64 to 8.0.32
Microsoft.NETCore.App.Runtime.win-arm64 fixed: 8.0.32
Upgrade Microsoft.NETCore.App.Runtime.win-arm64 to 8.0.32
Microsoft.NETCore.App.Runtime.win-x64 fixed: 8.0.32
Upgrade Microsoft.NETCore.App.Runtime.win-x64 to 8.0.32
Microsoft.NETCore.App.Runtime.win-x86 fixed: 8.0.32
Upgrade Microsoft.NETCore.App.Runtime.win-x86 to 8.0.32
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for Microsoft.NETCore.App.Runtime.linux-arm

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-66822, inspect your project dependencies for Microsoft.NETCore.App.Runtime.linux arm:

inspect dependencies for Microsoft.NETCore.App.Runtime.linux-arm

Analyze the terminal output to locate any version of Microsoft.NETCore.App.Runtime.linux arm in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 9.0.21), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-201: Insertion of Sensitive Information Into Sent Data, where the code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor. In Microsoft.NETCore.App.Runtime.linux arm, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Executive summary Microsoft is releasing this security advisory to provide information about a vulnerability in System.Net.Http. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. SocketsHttpHandler can retain a `Proxy-Authorization` header across an HTTP redirect and leak basic proxy credentials to the destination server. ## Announcement Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/448 ## CVSS Details - **Version:** 3.1 - **Severity:** Moderate - **Score:** 5.9 - **Vector:** `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N` - **Weakness:** CWE-201 (Insertion of Sensitive Information Into Sent Data) ## Affected Platforms - **Platforms:** Windows, Linux, macOS - **Architectures:** All ## <a name="affected-packages"></a>Affected Packages The vulnerability affects Microsoft .NET projects that use an affected package version listed below. Package name | Affected version | Patched version ------------ | ---------------- | --------------- [Microsoft.NETCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-x64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-x64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-arm64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-x64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x86) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-x64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-x64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-arm64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-x64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x86) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-x64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-x64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-arm64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-x64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x86) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-x64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-x64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-arm64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-x64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x86) | >= 8.0.0, <= 8.0.31 | 8.0.32 ## Advisory FAQ ### <a name="how-affected"></a>How do I know if I am affected? If using a package listed in [affected packages](#affected-packages), you're exposed to the vulnerability. ### <a name="how-fix"></a>How do I fix the issue? 1. To fix the issue please install the latest version of .NET. If you have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt you to update Visual Studio, which will also update your .NET SDKs. 2. If your application references the vulnerable package, update the package reference to the patched version. You can list the versions you have installed by running the `dotnet --info` command. Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed [self-contained applications](https://docs.microsoft.com/dotnet/core/deploying/#self-contained-deployments-scd) targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. ## Other Information ### Reporting Security Issues If you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the [MSRC Researcher Portal](https://msrc.microsoft.com/report/vulnerability/new). Further information can be found in the MSRC [Report an Issue FAQ](https://www.microsoft.com/msrc/faqs-report-an-issue). Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. ### Support You can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. ### Disclaimer The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. ### External Links [CVE-2026-66822](https://www.cve.org/CVERecord?id=CVE-2026-66822) ### Acknowledgements - Ky0toFu (@ky0tofu) - jhanks - Lucas Futures - Wenhan Zhou - Weeraphat Srisutham - Brent Woodard (@crusader_sec) with Crusader Security, LLC (https://crusaderproxy.com/) - Kevin Schmidt - Piotr Pietruszewski - Leandro Batista - Raffaello Tamagnini - Harkenzo - Anonymous - Attila.Cs (zerodaybugs.com) with https://zerodaybugs.com/ - l8BL with ENKI WhiteHat (https://www.enki.co.kr/) - caveeroo (https://caveeroo.dev/) with Tarlogic (https://www.tarlogic.com/) ### Revisions V1.0 (10/13/2026): Advisory published.

CVE-2026-66822 Affected Microsoft.NETCore.App.Runtime.linux arm Versions

44 component(s)
Fixed Versions:
9.0.2111.0.0-rc.210.0.138.0.32
Product / Package Ecosystem Affected Versions Fixed Version
Microsoft.NETCore.App.Runtime.linux-arm
NuGet
≥ 9.0.0
< 9.0.21
9.0.21
Microsoft.NETCore.App.Runtime.linux-arm64
NuGet
≥ 9.0.0
< 9.0.21
9.0.21
Microsoft.NETCore.App.Runtime.linux-musl-arm
NuGet
≥ 9.0.0
< 9.0.21
9.0.21
Microsoft.NETCore.App.Runtime.linux-musl-arm64
NuGet
≥ 9.0.0
< 9.0.21
9.0.21
Microsoft.NETCore.App.Runtime.linux-musl-x64
NuGet
≥ 9.0.0
< 9.0.21
9.0.21
Microsoft.NETCore.App.Runtime.linux-x64
NuGet
≥ 9.0.0
< 9.0.21
9.0.21
Microsoft.NETCore.App.Runtime.osx-arm64
NuGet
≥ 9.0.0
< 9.0.21
9.0.21
Microsoft.NETCore.App.Runtime.osx-x64
NuGet
≥ 9.0.0
< 9.0.21
9.0.21
Microsoft.NETCore.App.Runtime.win-arm64
NuGet
≥ 9.0.0
< 9.0.21
9.0.21
Microsoft.NETCore.App.Runtime.win-x64
NuGet
≥ 9.0.0
< 9.0.21
9.0.21
Microsoft.NETCore.App.Runtime.win-x86
NuGet
≥ 9.0.0
< 9.0.21
9.0.21
Microsoft.NETCore.App.Runtime.linux-arm
NuGet
≥ 11.0.0-preview.1
< 11.0.0-rc.2
11.0.0-rc.2
Microsoft.NETCore.App.Runtime.linux-arm64
NuGet
≥ 11.0.0-preview.1
< 11.0.0-rc.2
11.0.0-rc.2
Microsoft.NETCore.App.Runtime.linux-musl-arm
NuGet
≥ 11.0.0-preview.1
< 11.0.0-rc.2
11.0.0-rc.2
Microsoft.NETCore.App.Runtime.linux-musl-arm64
NuGet
≥ 11.0.0-preview.1
< 11.0.0-rc.2
11.0.0-rc.2
Microsoft.NETCore.App.Runtime.linux-musl-x64
NuGet
≥ 11.0.0-preview.1
< 11.0.0-rc.2
11.0.0-rc.2
Microsoft.NETCore.App.Runtime.linux-x64
NuGet
≥ 11.0.0-preview.1
< 11.0.0-rc.2
11.0.0-rc.2
Microsoft.NETCore.App.Runtime.osx-arm64
NuGet
≥ 11.0.0-preview.1
< 11.0.0-rc.2
11.0.0-rc.2
Microsoft.NETCore.App.Runtime.osx-x64
NuGet
≥ 11.0.0-preview.1
< 11.0.0-rc.2
11.0.0-rc.2
Microsoft.NETCore.App.Runtime.win-arm64
NuGet
≥ 11.0.0-preview.1
< 11.0.0-rc.2
11.0.0-rc.2
Microsoft.NETCore.App.Runtime.win-x64
NuGet
≥ 11.0.0-preview.1
< 11.0.0-rc.2
11.0.0-rc.2
Microsoft.NETCore.App.Runtime.win-x86
NuGet
≥ 11.0.0-preview.1
< 11.0.0-rc.2
11.0.0-rc.2
Microsoft.NETCore.App.Runtime.linux-arm
NuGet
≥ 10.0.0
< 10.0.13
10.0.13
Microsoft.NETCore.App.Runtime.linux-arm64
NuGet
≥ 10.0.0
< 10.0.13
10.0.13
Microsoft.NETCore.App.Runtime.linux-musl-arm
NuGet
≥ 10.0.0
< 10.0.13
10.0.13
Microsoft.NETCore.App.Runtime.linux-musl-arm64
NuGet
≥ 10.0.0
< 10.0.13
10.0.13
Microsoft.NETCore.App.Runtime.linux-musl-x64
NuGet
≥ 10.0.0
< 10.0.13
10.0.13
Microsoft.NETCore.App.Runtime.linux-x64
NuGet
≥ 10.0.0
< 10.0.13
10.0.13
Microsoft.NETCore.App.Runtime.osx-arm64
NuGet
≥ 10.0.0
< 10.0.13
10.0.13
Microsoft.NETCore.App.Runtime.osx-x64
NuGet
≥ 10.0.0
< 10.0.13
10.0.13
Microsoft.NETCore.App.Runtime.win-arm64
NuGet
≥ 10.0.0
< 10.0.13
10.0.13
Microsoft.NETCore.App.Runtime.win-x64
NuGet
≥ 10.0.0
< 10.0.13
10.0.13
Microsoft.NETCore.App.Runtime.win-x86
NuGet
≥ 10.0.0
< 10.0.13
10.0.13
Microsoft.NETCore.App.Runtime.linux-arm
NuGet
≥ 8.0.0
< 8.0.32
8.0.32
Microsoft.NETCore.App.Runtime.linux-arm64
NuGet
≥ 8.0.0
< 8.0.32
8.0.32
Microsoft.NETCore.App.Runtime.linux-musl-arm
NuGet
≥ 8.0.0
< 8.0.32
8.0.32
Microsoft.NETCore.App.Runtime.linux-musl-arm64
NuGet
≥ 8.0.0
< 8.0.32
8.0.32
Microsoft.NETCore.App.Runtime.linux-musl-x64
NuGet
≥ 8.0.0
< 8.0.32
8.0.32
Microsoft.NETCore.App.Runtime.linux-x64
NuGet
≥ 8.0.0
< 8.0.32
8.0.32
Microsoft.NETCore.App.Runtime.osx-arm64
NuGet
≥ 8.0.0
< 8.0.32
8.0.32
Microsoft.NETCore.App.Runtime.osx-x64
NuGet
≥ 8.0.0
< 8.0.32
8.0.32
Microsoft.NETCore.App.Runtime.win-arm64
NuGet
≥ 8.0.0
< 8.0.32
8.0.32
Microsoft.NETCore.App.Runtime.win-x64
NuGet
≥ 8.0.0
< 8.0.32
8.0.32
Microsoft.NETCore.App.Runtime.win-x86
NuGet
≥ 8.0.0
< 8.0.32
8.0.32

References

Frequently Asked Questions

What is CVE-2026-66822?
CVE-2026-66822 is a security vulnerability in Microsoft.NETCore.App.Runtime.linux arm involving Microsoft Security Advisory CVE-2026-66822 - .NET and Visual Studio Information Disclosure Vulnerability under CWE-201: Insertion of Sensitive Information Into Sent Data.
Which Microsoft.NETCore.App.Runtime.linux arm versions are affected?
Affected versions include releases prior to 9.0.21, 11.0.0-rc.2, 10.0.13, 8.0.32 across affected packages: Microsoft.NETCore.App.Runtime.linux-arm, Microsoft.NETCore.App.Runtime.linux-arm64, Microsoft.NETCore.App.Runtime.linux-musl-arm, Microsoft.NETCore.App.Runtime.linux-musl-arm64, Microsoft.NETCore.App.Runtime.linux-musl-x64, Microsoft.NETCore.App.Runtime.linux-x64, Microsoft.NETCore.App.Runtime.osx-arm64, Microsoft.NETCore.App.Runtime.osx-x64, Microsoft.NETCore.App.Runtime.win-arm64, Microsoft.NETCore.App.Runtime.win-x64, Microsoft.NETCore.App.Runtime.win-x86.
What version fixes CVE-2026-66822?
Upgrading to 9.0.21, 11.0.0-rc.2, 10.0.13, 8.0.32 (or the latest patched release for your respective branch) resolves the vulnerability.
Is Microsoft.NETCore.App.Runtime.linux-arm affected?
Yes, Microsoft.NETCore.App.Runtime.linux-arm is affected in releases prior to 9.0.21, 11.0.0-rc.2, 10.0.13, 8.0.32. Upgrade your dependency to 9.0.21, 11.0.0-rc.2, 10.0.13, 8.0.32 or later.
Is Microsoft.NETCore.App.Runtime.linux-arm64 affected?
Yes, Microsoft.NETCore.App.Runtime.linux-arm64 is affected in releases prior to 9.0.21, 11.0.0-rc.2, 10.0.13, 8.0.32. Upgrade your dependency to 9.0.21, 11.0.0-rc.2, 10.0.13, 8.0.32 or later.
What is the CVSS score of CVE-2026-66822?
CVE-2026-66822 has a CVSS v3.1 base score of 5.9 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2026-66822?
CVE-2026-66822 is classified under CWE-201: Insertion of Sensitive Information Into Sent Data (The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.).
How can I check NuGet dependencies for CVE-2026-66822?
Run the dependency tree command: 'inspect dependencies for Microsoft.NETCore.App.Runtime.linux-arm'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-wxxw-5cvc-53j7",
  "modified" : "2026-10-13T20:41:41Z",
  "published" : "2026-10-13T20:41:40Z",
  "aliases" : [ "CVE-2026-66822" ],
  "summary" : "Microsoft Security Advisory CVE-2026-66822 - .NET and Visual Studio Information Disclosure Vulnerability",
  "details" : "## Executive summary\n\nMicrosoft is releasing this security advisory to provide information about a vulnerability in System.Net.Http. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.\n\nSocketsHttpHandler can retain a `Proxy-Authorization` header across an HTTP redirect and leak basic proxy credentials to the destination server.\n\n## Announcement\n\nAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/448\n\n## CVSS Details\n\n- **Version:** 3.1\n- **Severity:** Moderate\n- **Score:** 5.9\n- **Vector:** `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N`\n- **Weakness:** CWE-201 (Insertion of Sensitive Information Into Sent Data)\n\n## Affected Platforms\n\n- **Platforms:** Windows, Linux, macOS\n- **Architectures:** All\n\n## <a name=\"affected-packages\"></a>Affected Packages\n\nThe vulnerability affects Microsoft .NET projects that use an affected package version listed below.\n\nPackage name | Affected version | Patched version\n------------ | ---------------- | ---------------\n[Microsoft.NETCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm) | >= 9.0.0, <= 9.0.20 | 9.0.21\n[Microsoft.NETCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm64) | >= 9.0.0, <= 9.0.20 | 9.0.21\n[Microsoft.NETCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm) | >= 9.0.0, <= 9.0.20 | 9.0.21\n[Microsoft.NETCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm64) | >= 9.0.0, <= 9.0.20 | 9.0.21\n[Microsoft.NETCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-x64) | >= 9.0.0, <= 9.0.20 | 9.0.21\n[Microsoft.NETCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-x64) | >= 9.0.0, <= 9.0.20 | 9.0.21\n[Microsoft.NETCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-arm64) | >= 9.0.0, <= 9.0.20 | 9.0.21\n[Microsoft.NETCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-x64) | >= 9.0.0, <= 9.0.20 | 9.0.21\n[Microsoft.NETCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm) | >= 9.0.0, <= 9.0.20 | 9.0.21\n[Microsoft.NETCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm64) | >= 9.0.0, <= 9.0.20 | 9.0.21\n[Microsoft.NETCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x64) | >= 9.0.0, <= 9.0.20 | 9.0.21\n[Microsoft.NETCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x86) | >= 9.0.0, <= 9.0.20 | 9.0.21\n[Microsoft.NETCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2\n[Microsoft.NETCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2\n[Microsoft.NETCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2\n[Microsoft.NETCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2\n[Microsoft.NETCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-x64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2\n[Microsoft.NETCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-x64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2\n[Microsoft.NETCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-arm64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2\n[Microsoft.NETCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-x64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2\n[Microsoft.NETCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2\n[Microsoft.NETCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2\n[Microsoft.NETCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2\n[Microsoft.NETCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x86) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2\n[Microsoft.NETCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm) | >= 10.0.0, <= 10.0.12 | 10.0.13\n[Microsoft.NETCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm64) | >= 10.0.0, <= 10.0.12 | 10.0.13\n[Microsoft.NETCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm) | >= 10.0.0, <= 10.0.12 | 10.0.13\n[Microsoft.NETCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm64) | >= 10.0.0, <= 10.0.12 | 10.0.13\n[Microsoft.NETCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-x64) | >= 10.0.0, <= 10.0.12 | 10.0.13\n[Microsoft.NETCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-x64) | >= 10.0.0, <= 10.0.12 | 10.0.13\n[Microsoft.NETCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-arm64) | >= 10.0.0, <= 10.0.12 | 10.0.13\n[Microsoft.NETCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-x64) | >= 10.0.0, <= 10.0.12 | 10.0.13\n[Microsoft.NETCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm) | >= 10.0.0, <= 10.0.12 | 10.0.13\n[Microsoft.NETCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm64) | >= 10.0.0, <= 10.0.12 | 10.0.13\n[Microsoft.NETCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x64) | >= 10.0.0, <= 10.0.12 | 10.0.13\n[Microsoft.NETCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x86) | >= 10.0.0, <= 10.0.12 | 10.0.13\n[Microsoft.NETCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm) | >= 8.0.0, <= 8.0.31 | 8.0.32\n[Microsoft.NETCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm64) | >= 8.0.0, <= 8.0.31 | 8.0.32\n[Microsoft.NETCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm) | >= 8.0.0, <= 8.0.31 | 8.0.32\n[Microsoft.NETCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm64) | >= 8.0.0, <= 8.0.31 | 8.0.32\n[Microsoft.NETCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-x64) | >= 8.0.0, <= 8.0.31 | 8.0.32\n[Microsoft.NETCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-x64) | >= 8.0.0, <= 8.0.31 | 8.0.32\n[Microsoft.NETCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-arm64) | >= 8.0.0, <= 8.0.31 | 8.0.32\n[Microsoft.NETCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-x64) | >= 8.0.0, <= 8.0.31 | 8.0.32\n[Microsoft.NETCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm) | >= 8.0.0, <= 8.0.31 | 8.0.32\n[Microsoft.NETCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm64) | >= 8.0.0, <= 8.0.31 | 8.0.32\n[Microsoft.NETCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x64) | >= 8.0.0, <= 8.0.31 | 8.0.32\n[Microsoft.NETCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x86) | >= 8.0.0, <= 8.0.31 | 8.0.32\n\n## Advisory FAQ\n\n### <a name=\"how-affected\"></a>How do I know if I am affected?\n\nIf using a package listed in [affected packages](#affected-packages), you're exposed to the vulnerability.\n\n### <a name=\"how-fix\"></a>How do I fix the issue?\n\n1. To fix the issue please install the latest version of .NET. If you have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt you to update Visual Studio, which will also update your .NET SDKs.\n2. If your application references the vulnerable package, update the package reference to the patched version. You can list the versions you have installed by running the `dotnet --info` command.\n\nOnce you have installed the updated runtime or SDK, restart your apps for the update to take effect.\n\nAdditionally, if you've deployed [self-contained applications](https://docs.microsoft.com/dotnet/core/deploying/#self-contained-deployments-scd) targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed.\n\n## Other Information\n\n### Reporting Security Issues\n\nIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the [MSRC Researcher Portal](https://msrc.microsoft.com/report/vulnerability/new). Further information can be found in the MSRC [Report an Issue FAQ](https://www.microsoft.com/msrc/faqs-report-an-issue).\n\nSecurity reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty.\n\n### Support\n\nYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue.\n\n### Disclaimer\n\nThe information provided in this advisory is provided \"as is\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.\n\n### External Links\n\n[CVE-2026-66822](https://www.cve.org/CVERecord?id=CVE-2026-66822)\n\n### Acknowledgements\n\n- Ky0toFu (@ky0tofu)\n- jhanks\n- Lucas Futures\n- Wenhan Zhou\n- Weeraphat Srisutham\n- Brent Woodard (@crusader_sec) with Crusader Security, LLC (https://crusaderproxy.com/)\n- Kevin Schmidt\n- Piotr Pietruszewski\n- Leandro Batista\n- Raffaello Tamagnini\n- Harkenzo\n- Anonymous\n- Attila.Cs (zerodaybugs.com) with https://zerodaybugs.com/\n- l8BL with ENKI WhiteHat (https://www.enki.co.kr/)\n- caveeroo (https://caveeroo.dev/) with Tarlogic (https://www.tarlogic.com/)\n\n### Revisions\n\nV1.0 (10/13/2026): Advisory published.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-arm"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.0.21"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 9.0.20"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.0.21"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 9.0.20"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-musl-arm"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.0.21"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 9.0.20"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-musl-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.0.21"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 9.0.20"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-musl-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.0.21"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 9.0.20"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.0.21"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 9.0.20"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.osx-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.0.21"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 9.0.20"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.osx-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.0.21"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 9.0.20"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.win-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.0.21"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 9.0.20"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.win-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.0.21"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 9.0.20"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.win-x86"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.0.21"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 9.0.20"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-arm"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0-preview.1"
      }, {
        "fixed" : "11.0.0-rc.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 11.0.0-rc.1"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0-preview.1"
      }, {
        "fixed" : "11.0.0-rc.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 11.0.0-rc.1"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-musl-arm"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0-preview.1"
      }, {
        "fixed" : "11.0.0-rc.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 11.0.0-rc.1"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-musl-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0-preview.1"
      }, {
        "fixed" : "11.0.0-rc.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 11.0.0-rc.1"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-musl-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0-preview.1"
      }, {
        "fixed" : "11.0.0-rc.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 11.0.0-rc.1"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0-preview.1"
      }, {
        "fixed" : "11.0.0-rc.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 11.0.0-rc.1"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.osx-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0-preview.1"
      }, {
        "fixed" : "11.0.0-rc.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 11.0.0-rc.1"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.osx-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0-preview.1"
      }, {
        "fixed" : "11.0.0-rc.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 11.0.0-rc.1"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.win-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0-preview.1"
      }, {
        "fixed" : "11.0.0-rc.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 11.0.0-rc.1"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.win-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0-preview.1"
      }, {
        "fixed" : "11.0.0-rc.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 11.0.0-rc.1"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.win-x86"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0-preview.1"
      }, {
        "fixed" : "11.0.0-rc.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 11.0.0-rc.1"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-arm"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.0.0"
      }, {
        "fixed" : "10.0.13"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.0.12"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.0.0"
      }, {
        "fixed" : "10.0.13"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.0.12"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-musl-arm"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.0.0"
      }, {
        "fixed" : "10.0.13"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.0.12"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-musl-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.0.0"
      }, {
        "fixed" : "10.0.13"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.0.12"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-musl-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.0.0"
      }, {
        "fixed" : "10.0.13"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.0.12"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.0.0"
      }, {
        "fixed" : "10.0.13"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.0.12"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.osx-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.0.0"
      }, {
        "fixed" : "10.0.13"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.0.12"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.osx-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.0.0"
      }, {
        "fixed" : "10.0.13"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.0.12"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.win-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.0.0"
      }, {
        "fixed" : "10.0.13"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.0.12"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.win-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.0.0"
      }, {
        "fixed" : "10.0.13"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.0.12"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.win-x86"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.0.0"
      }, {
        "fixed" : "10.0.13"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.0.12"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-arm"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.0.32"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 8.0.31"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.0.32"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 8.0.31"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-musl-arm"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.0.32"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 8.0.31"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-musl-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.0.32"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 8.0.31"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-musl-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.0.32"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 8.0.31"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.linux-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.0.32"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 8.0.31"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.osx-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.0.32"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 8.0.31"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.osx-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.0.32"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 8.0.31"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.win-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.0.32"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 8.0.31"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.win-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.0.32"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 8.0.31"
    }
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Runtime.win-x86"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.0.32"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 8.0.31"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/dotnet/runtime/security/advisories/GHSA-wxxw-5cvc-53j7"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/dotnet/announcements/issues/448"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/dotnet/runtime/issues/135697"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/dotnet/runtime"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-201" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-13T20:41:40Z",
    "nvd_published_at" : null
  }
}