CVE-2026-39832: Golang.org/x/crypto Golang.org/x/crypto Doesn't Drop Invoking Agent Vulnerability

CRITICAL
Advisory Identifier: GHSA-f5wc-c3c7-36mc
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CVSS 9.1
CWE-502 CWE-281
Published
Advisory Summary

CVE-2026-39832 is a CRITICAL (CVSS 9.1) golang.org/x/crypto doesn't drop invoking agent vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Golang.org/x/crypto libraries in the Go ecosystem. The issue involves golang.org/x/crypto doesn't drop invoking agent constraints when forwarding keys. Remediation is available by upgrading affected packages to version 0.52.0.

CVE-2026-39832 at a Glance

CVE Identifier CVE-2026-39832
GHSA Identifier GHSA-f5wc-c3c7-36mc
Severity CRITICAL
CVSS v3.1 Base Score 9.1
CWE Classification CWE-502: Deserialization of Untrusted Data
Affected Product Golang.org/x/crypto
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 9.1

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

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

How to Fix CVE-2026-39832

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

golang.org/x/crypto fixed: 0.52.0 
Upgrade golang.org/x/crypto to 0.52.0
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 golang.org/x/crypto

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-39832, inspect your project dependencies for Golang.org/x/crypto:

inspect dependencies for golang.org/x/crypto

Analyze the terminal output to locate any version of Golang.org/x/crypto in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.52.0), 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-502: Deserialization of Untrusted Data, where the product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. In Golang.org/x/crypto, 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

When adding a key to a remote agent constraint extensions such as restrict-destination-v00@openssh.com were not serialized in the request. Destination restrictions were silently stripped when forwarding keys, allowing unrestricted use of the key on the remote host. The client now serializes all constraint extensions. Additionally, the in-memory keyring returned by NewKeyring() now rejects keys with unsupported constraint extensions instead of silently ignoring them.

CVE-2026-39832 Affected Golang.org/x/crypto Versions

1 component(s)
Fixed Versions:
0.52.0
Product / Package Ecosystem Affected Versions Fixed Version
golang.org/x/crypto
golang/golang.org/x/crypto
Go
< 0.52.0
0.52.0

References

NVD — CVE-2026-39832 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-39832
access.redhat.com/errata/rhsa-2026:35... WEB
https://access.redhat.com/errata/RHSA-2026:35833
access.redhat.com/errata/rhsa-2026:41... WEB
https://access.redhat.com/errata/RHSA-2026:41036
access.redhat.com/errata/rhsa-2026:41... WEB
https://access.redhat.com/errata/RHSA-2026:41066
access.redhat.com/errata/rhsa-2026:42... WEB
https://access.redhat.com/errata/RHSA-2026:42146
access.redhat.com/errata/rhsa-2026:42... WEB
https://access.redhat.com/errata/RHSA-2026:42796
access.redhat.com/errata/rhsa-2026:43... WEB
https://access.redhat.com/errata/RHSA-2026:43052
access.redhat.com/errata/rhsa-2026:43... WEB
https://access.redhat.com/errata/RHSA-2026:43692
access.redhat.com/errata/rhsa-2026:49... WEB
https://access.redhat.com/errata/RHSA-2026:49944
access.redhat.com/errata/rhsa-2026:52... WEB
https://access.redhat.com/errata/RHSA-2026:52857
access.redhat.com/errata/rhsa-2026:52... WEB
https://access.redhat.com/errata/RHSA-2026:52910
Golang.org/x/crypto Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2026-39832
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2480685
cs.opensource.google/go/x/crypto PACKAGE
https://cs.opensource.google/go/x/crypto
go.dev/cl/778642 WEB
https://go.dev/cl/778642
go.dev/issue/79435 WEB
https://go.dev/issue/79435
groups.google.com/g/golang-announce/c... WEB
https://groups.google.com/g/golang-announce/c/a082jnz-LvI
pkg.go.dev/vuln/go-2026-5006 WEB
https://pkg.go.dev/vuln/GO-2026-5006
Golang.org/x/crypto Security Information SECURITY
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39832.json
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36199
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36319
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36625
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36648
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36651
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36796
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36797
access.redhat.com/errata/rhsa-2026:37... WEB
https://access.redhat.com/errata/RHSA-2026:37072
access.redhat.com/errata/rhsa-2026:37... WEB
https://access.redhat.com/errata/RHSA-2026:37123
access.redhat.com/errata/rhsa-2026:37... WEB
https://access.redhat.com/errata/RHSA-2026:37271
access.redhat.com/errata/rhsa-2026:37... WEB
https://access.redhat.com/errata/RHSA-2026:37387
access.redhat.com/errata/rhsa-2026:37... WEB
https://access.redhat.com/errata/RHSA-2026:37410
access.redhat.com/errata/rhsa-2026:40... WEB
https://access.redhat.com/errata/RHSA-2026:40118
access.redhat.com/errata/rhsa-2026:40... WEB
https://access.redhat.com/errata/RHSA-2026:40262
access.redhat.com/errata/rhsa-2026:40... WEB
https://access.redhat.com/errata/RHSA-2026:40945
access.redhat.com/errata/rhsa-2026:40... WEB
https://access.redhat.com/errata/RHSA-2026:40972
access.redhat.com/errata/rhsa-2026:41... WEB
https://access.redhat.com/errata/RHSA-2026:41019
access.redhat.com/errata/rhsa-2026:41... WEB
https://access.redhat.com/errata/RHSA-2026:41031

Frequently Asked Questions

What is CVE-2026-39832?
CVE-2026-39832 is a security vulnerability in Golang.org/x/crypto involving golang.org/x/crypto doesn't drop invoking agent constraints when forwarding keys under CWE-502: Deserialization of Untrusted Data.
Which Golang.org/x/crypto versions are affected?
Affected versions include releases prior to 0.52.0 across affected packages: golang.org/x/crypto.
What version fixes CVE-2026-39832?
Upgrading to 0.52.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is golang.org/x/crypto affected?
Yes, golang.org/x/crypto is affected in releases prior to 0.52.0. Upgrade your dependency to 0.52.0 or later.
What is the CVSS score of CVE-2026-39832?
CVE-2026-39832 has a CVSS v3.1 base score of 9.1 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2026-39832?
CVE-2026-39832 is classified under CWE-502: Deserialization of Untrusted Data (The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.).
How can I check Go dependencies for CVE-2026-39832?
Run the dependency tree command: 'inspect dependencies for golang.org/x/crypto'. 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 
{
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  "id" : "GHSA-f5wc-c3c7-36mc",
  "modified" : "2026-08-11T15:31:42Z",
  "published" : "2026-06-25T22:14:00Z",
  "aliases" : [ "CVE-2026-39832" ],
  "summary" : "golang.org/x/crypto doesn't drop invoking agent constraints when forwarding keys",
  "details" : "When adding a key to a remote agent constraint extensions such as restrict-destination-v00@openssh.com were not serialized in the request. Destination restrictions were silently stripped when forwarding keys, allowing unrestricted use of the key on the remote host. The client now serializes all constraint extensions. Additionally, the in-memory keyring returned by NewKeyring() now rejects keys with unsupported constraint extensions instead of silently ignoring them.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
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      "ecosystem" : "Go",
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    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.52.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-39832"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:35833"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:41036"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:41066"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:42146"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:42796"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:43052"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:43692"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:49944"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:52857"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:52910"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/security/cve/CVE-2026-39832"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2480685"
  }, {
    "type" : "PACKAGE",
    "url" : "https://cs.opensource.google/go/x/crypto"
  }, {
    "type" : "WEB",
    "url" : "https://go.dev/cl/778642"
  }, {
    "type" : "WEB",
    "url" : "https://go.dev/issue/79435"
  }, {
    "type" : "WEB",
    "url" : "https://groups.google.com/g/golang-announce/c/a082jnz-LvI"
  }, {
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    "url" : "https://pkg.go.dev/vuln/GO-2026-5006"
  }, {
    "type" : "WEB",
    "url" : "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39832.json"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:36199"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:36319"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:36625"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:36648"
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    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:36651"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:36796"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:36797"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:37072"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:37123"
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    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:37271"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:37387"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:37410"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:40118"
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    "url" : "https://access.redhat.com/errata/RHSA-2026:40262"
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    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:40945"
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    "url" : "https://access.redhat.com/errata/RHSA-2026:40972"
  }, {
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    "url" : "https://access.redhat.com/errata/RHSA-2026:41019"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:41031"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-281", "CWE-502" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-25T22:14:00Z",
    "nvd_published_at" : "2026-05-22T04:16:22Z"
  }
}