What is CVE-2025-39764?

CVE-2025-39764 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 2.6.23 onward and patched in 5.10.253, 5.15.203, 6.1.167 and others. CVE-2025-39764 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-39764?

CVE-2025-39764 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2025-39764?

Yes, CVE-2025-39764 has been patched. Fixed versions include 5.10.253, 5.15.203, 6.1.167 and others. If you are running Linux kernel 2.6.23 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-39764 actively exploited?

CVE-2025-39764 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2025-39764

Medium

In the Linux kernel, the following vulnerability has been resolved: netfilter: ctnetlink: remove refcounting in expectation dumpers Same pattern as previous patch: do not keep the expectation object alive via refcount, only store a cookie value and then use that as the skip hint for dump resumption. AFAICS this has the same issue as the one resolved in the conntrack dumper, when we do if (!refcount_inc_not_zero(&exp->use)) to increment the refcount, there is a chance that exp == last, which causes a double-increment of the refcount and subsequent memory leak.

Package Linux Kernel

Published 2025-09-11

Last modified 2026-04-18

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Affected versions

Linux kernel versions 2.6.23 and later are affected. Fixed in 5.10.253, 5.15.203, 6.1.167, 6.6.130, 6.12.78, 6.16.2, 6.17 and their respective stable series.

Affected from

≥ 2.6.23

Fixed in

✓ 5.10.253 5.10.x ✓ 5.15.203 5.15.x ✓ 6.1.167 6.1.x ✓ 6.6.130 6.6.x ✓ 6.12.78 6.12.x ✓ 6.16.2 6.16.x ✓ 6.17

References

The following references provide additional information about CVE-2025-39764 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/078d33c95bf534d37aa04269d1ae6158e20082d5
Patch
Kernel patch commit
https://git.kernel.org/stable/c/1492e3dcb2be3aa46d1963da96aa9593e4e4db5a
Patch
Kernel patch commit
https://git.kernel.org/stable/c/64b7684042246e3238464c66894e30ba30c7e851
Patch

7 patch commits total View all on NVD

Details

CVE ID CVE-2025-39764

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2025-09-11

Modified 2026-04-18

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2025-39764?

CVE-2025-39764 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 2.6.23 onward and has been patched in 5.10.253, 5.15.203, 6.1.167 and others. CVE-2025-39764 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-39764?

CVE-2025-39764 has a CVSS score of 5.5 out of 10, rated Medium 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:H.
Is there a patch available for CVE-2025-39764?

Yes — CVE-2025-39764 has been patched. Fixed versions include 5.10.253, 5.15.203, 6.1.167 and others. If you are running Linux kernel 2.6.23 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-39764 actively exploited?

No — CVE-2025-39764 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.