CVE-2026-25592: Semantic kernel Semantic Kernel Has Arbitrary File Vulnerability

CRITICAL
Advisory Identifier: GHSA-2ww3-72rp-wpp4
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CVSS 9.9
CWE-22
Published
Advisory Summary

CVE-2026-25592 is a CRITICAL (CVSS 9.9) semantic kernel has arbitrary file vulnerability (CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) affecting Semantic kernel libraries in the PyPI ecosystem. The issue involves semantic kernel has arbitrary file write via ai agent function calling in .net sdk. Remediation is available by upgrading affected packages to version 1.39.3, 1.71.0.

CVE-2026-25592 at a Glance

CVE Identifier CVE-2026-25592
GHSA Identifier GHSA-2ww3-72rp-wpp4
Severity CRITICAL
CVSS v3.1 Base Score 9.9
CWE Classification CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Product Semantic kernel
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 9.9

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

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

How to Fix CVE-2026-25592

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

semantic-kernel fixed: 1.39.3 
pip install semantic-kernel>=1.39.3
Microsoft.SemanticKernel.Core fixed: 1.71.0 
Upgrade Microsoft.SemanticKernel.Core to 1.71.0
Verify Direct and Transitive Dependencies

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

pip show semantic-kernel

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-25592, inspect your installed packages using pip:

pip show semantic-kernel

Analyze the terminal output to locate any version of Semantic kernel in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.39.3), your application is affected.

Note: The pip show semantic-kernel command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'), where the product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. In Semantic kernel, 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

### Impact _What kind of vulnerability is it? Who is impacted?_ An Arbitrary File Write vulnerability has been identified in Microsoft's Semantic Kernel .NET SDK, specifically within the `SessionsPythonPlugin`. Developers who have built applications which include Microsoft's Semantic Kernel .NET SDK and are using the `SessionsPythonPlugin` ### Patches _Has the problem been patched? What versions should users upgrade to?_ The problem has been fixed in [Microsoft.SemanticKernel.Plugins.Core version 1.71.0](https://www.nuget.org/packages/Microsoft.SemanticKernel.Plugins.Core/1.71.0). Users should upgrade to version 1.71.0 or higher. ### Workarounds _Is there a way for users to fix or remediate the vulnerability without upgrading?_ Users can create a [Function Invocation Filter](https://learn.microsoft.com/en-us/semantic-kernel/concepts/enterprise-readiness/filters?pivots=programming-language-csharp#function-invocation-filter) which checks the arguments being passed to any calls to `DownloadFileAsync ` or `UploadFileAsync` and ensures the provided `localFilePath` is allow listed. ### References _Are there any links users can visit to find out more?_ - [Sample showing safe use of the CodeInterpreterPlugin](https://github.com/microsoft/semantic-kernel/blob/main/dotnet/samples/Demos/CodeInterpreterPlugin/Program.cs#L61-L64) - [PR to Add file upload security controls to SessionsPythonPlugin](https://github.com/microsoft/semantic-kernel/pull/13478/changes#diff-88d3cacba2bfa84eef8f2aa171b34f9940338cbb784a3ffc49f5fe3af1b8943d)

CVE-2026-25592 Affected Semantic kernel Versions

2 component(s)
Fixed Versions:
1.39.31.71.0
Product / Package Ecosystem Affected Versions Fixed Version
semantic-kernel
pypi/semantic-kernel
PyPI
< 1.39.3
1.39.3
Microsoft.SemanticKernel.Core
nuget/Microsoft.SemanticKernel.Core
NuGet
< 1.71.0
1.71.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/microsoft/semantic-kernel/security/advisories/GHSA-2ww3-72rp-wpp4
NVD — CVE-2026-25592 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-25592
Semantic kernel Source Repository REPOSITORY
https://github.com/microsoft/semantic-kernel/pull/13478/changes#diff-88d3cacba2bfa84eef8f2aa171b34f9940338cbb784a3ffc49f5fe3af1b8943d
Semantic kernel Source Repository REPOSITORY
https://github.com/microsoft/semantic-kernel
Semantic kernel Source Repository REPOSITORY
https://github.com/microsoft/semantic-kernel/blob/main/dotnet/samples/Demos/CodeInterpreterPlugin/Program.cs#L61-L64

Frequently Asked Questions

What is CVE-2026-25592?
CVE-2026-25592 is a security vulnerability in Semantic kernel involving Semantic Kernel has Arbitrary File Write via AI Agent Function Calling in .NET SDK under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal').
Which Semantic kernel versions are affected?
Affected versions include releases prior to 1.39.3, 1.71.0 across affected packages: semantic-kernel, Microsoft.SemanticKernel.Core.
What version fixes CVE-2026-25592?
Upgrading to 1.39.3, 1.71.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is semantic-kernel affected?
Yes, semantic-kernel is affected in releases prior to 1.39.3. Upgrade your dependency to 1.39.3 or later.
Is Microsoft.SemanticKernel.Core affected?
Yes, Microsoft.SemanticKernel.Core is affected in releases prior to 1.71.0. Upgrade your dependency to 1.71.0 or later.
What is the CVSS score of CVE-2026-25592?
CVE-2026-25592 has a CVSS v3.1 base score of 9.9 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
What CWE is associated with CVE-2026-25592?
CVE-2026-25592 is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.).
How can I check PyPI dependencies for CVE-2026-25592?
Run the dependency tree command: 'pip show semantic-kernel'. 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
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-2ww3-72rp-wpp4",
  "modified" : "2026-02-20T19:15:43Z",
  "published" : "2026-02-06T18:37:24Z",
  "aliases" : [ "CVE-2026-25592" ],
  "summary" : "Semantic Kernel has Arbitrary File Write via AI Agent Function Calling in .NET SDK",
  "details" : "### Impact\n_What kind of vulnerability is it? Who is impacted?_\nAn Arbitrary File Write vulnerability has been identified in Microsoft's Semantic Kernel .NET SDK, specifically within the `SessionsPythonPlugin`.\nDevelopers who have built applications which include Microsoft's Semantic Kernel .NET SDK and are using the `SessionsPythonPlugin`\n\n### Patches\n_Has the problem been patched? What versions should users upgrade to?_\nThe problem has been fixed in [Microsoft.SemanticKernel.Plugins.Core version 1.71.0](https://www.nuget.org/packages/Microsoft.SemanticKernel.Plugins.Core/1.71.0). Users should upgrade to version 1.71.0 or higher.\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\nUsers can create a [Function Invocation Filter](https://learn.microsoft.com/en-us/semantic-kernel/concepts/enterprise-readiness/filters?pivots=programming-language-csharp#function-invocation-filter) which checks the arguments being passed to any calls to `DownloadFileAsync ` or `UploadFileAsync` and ensures the provided `localFilePath` is allow listed.\n\n### References\n_Are there any links users can visit to find out more?_\n- [Sample showing safe use of the CodeInterpreterPlugin](https://github.com/microsoft/semantic-kernel/blob/main/dotnet/samples/Demos/CodeInterpreterPlugin/Program.cs#L61-L64)\n- [PR to Add file upload security controls to SessionsPythonPlugin](https://github.com/microsoft/semantic-kernel/pull/13478/changes#diff-88d3cacba2bfa84eef8f2aa171b34f9940338cbb784a3ffc49f5fe3af1b8943d)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "semantic-kernel"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.39.3"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.SemanticKernel.Core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.71.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/microsoft/semantic-kernel/security/advisories/GHSA-2ww3-72rp-wpp4"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-25592"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/microsoft/semantic-kernel/pull/13478/changes#diff-88d3cacba2bfa84eef8f2aa171b34f9940338cbb784a3ffc49f5fe3af1b8943d"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/microsoft/semantic-kernel"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/microsoft/semantic-kernel/blob/main/dotnet/samples/Demos/CodeInterpreterPlugin/Program.cs#L61-L64"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-06T18:37:24Z",
    "nvd_published_at" : "2026-02-06T21:16:17Z"
  }
}