CVE-2025-39964 Affecting kernel6.12-tools package, versions <1:6.12.53-69.119.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.03% (9th percentile)

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  • Snyk IDSNYK-AMZN2023-KERNEL612TOOLS-13731040
  • published29 Oct 2025
  • disclosed13 Oct 2025

Introduced: 13 Oct 2025

NewCVE-2025-39964  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel6.12-tools to version 1:6.12.53-69.119.amzn2023 or higher.
This issue was patched in ALAS2023-2025-1254.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel6.12-tools package and not the kernel6.12-tools package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg

Issuing two writes to the same af_alg socket is bogus as the data will be interleaved in an unpredictable fashion. Furthermore, concurrent writes may create inconsistencies in the internal socket state.

Disallow this by adding a new ctx->write field that indiciates exclusive ownership for writing.

CVSS Base Scores

version 3.1