What is CVE-2025-39964?

CVE-2025-39964 is a Low severity Linux kernel vulnerability with a CVSS score of 3.3 out of 10, affecting Linux kernel versions from 2.6.38 onward and patched in 5.10.245, 5.15.194, 6.1.154 and others. CVE-2025-39964 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-39964?

CVE-2025-39964 has a CVSS score of 3.3 out of 10, rated Low severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.

Is there a patch available for CVE-2025-39964?

Yes, CVE-2025-39964 has been patched. Fixed versions include 5.10.245, 5.15.194, 6.1.154 and others. If you are running Linux kernel 2.6.38 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-39964 actively exploited?

CVE-2025-39964 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2025-39964

Low

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.

Package Linux Kernel

Published 2025-10-13

Last modified 2026-02-26

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

3.3

out of 10

Low

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

Low

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Affected versions

Linux kernel versions 2.6.38 and later are affected. Fixed in 5.10.245, 5.15.194, 6.1.154, 6.6.108, 6.12.49, 6.16.9, 6.17 and their respective stable series.

Affected from

≥ 2.6.38

Fixed in

✓ 5.10.245 5.10.x ✓ 5.15.194 5.15.x ✓ 6.1.154 6.1.x ✓ 6.6.108 6.6.x ✓ 6.12.49 6.12.x ✓ 6.16.9 6.16.x ✓ 6.17

References

The following references provide additional information about CVE-2025-39964 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/0f28c4adbc4a97437874c9b669fd7958a8c6d6ce
Patch
Kernel patch commit
https://git.kernel.org/stable/c/1b34cbbf4f011a121ef7b2d7d6e6920a036d5285
Patch
Kernel patch commit
https://git.kernel.org/stable/c/1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8
Patch

7 patch commits total View all on NVD

Details

CVE ID CVE-2025-39964

Severity Low

CVSS score 3.3 / 10

CVSS version 3.1

Published 2025-10-13

Modified 2026-02-26

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2025-39964?

CVE-2025-39964 is a Low severity Linux kernel vulnerability with a CVSS score of 3.3 out of 10 . It affects Linux kernel versions from 2.6.38 onward and has been patched in 5.10.245, 5.15.194, 6.1.154 and others. CVE-2025-39964 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-39964?

CVE-2025-39964 has a CVSS score of 3.3 out of 10, rated Low severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.
Is there a patch available for CVE-2025-39964?

Yes — CVE-2025-39964 has been patched. Fixed versions include 5.10.245, 5.15.194, 6.1.154 and others. If you are running Linux kernel 2.6.38 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-39964 actively exploited?

No — CVE-2025-39964 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.