What is CVE-2025-39777?

CVE-2025-39777 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 6.16 onward and patched in 6.16.4 and 6.17. CVE-2025-39777 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-39777?

CVE-2025-39777 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-2025-39777?

Yes, CVE-2025-39777 has been patched. Fixed versions include 6.16.4 and 6.17. If you are running Linux kernel 6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-39777 actively exploited?

CVE-2025-39777 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2025-39777

Medium

In the Linux kernel, the following vulnerability has been resolved: crypto: acomp - Fix CFI failure due to type punning To avoid a crash when control flow integrity is enabled, make the workspace ("stream") free function use a consistent type, and call it through a function pointer that has that same type.

Package Linux Kernel

Published 2025-09-11

Last modified 2025-11-25

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 6.16 and later are affected. Fixed in 6.16.4, 6.17 and their respective stable series.

Affected from

≥ 6.16

Fixed in

✓ 6.16.4 6.16.x ✓ 6.17

References

The following references provide additional information about CVE-2025-39777 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/7ec68c59461ca846aab9b7c2b39f63ac7c8a43cf
Patch
Kernel patch commit
https://git.kernel.org/stable/c/962ddc5a7a4b04c007bba0f3e7298cda13c62efd
Patch

Details

CVE ID CVE-2025-39777

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2025-09-11

Modified 2025-11-25

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2025-39777?

CVE-2025-39777 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.16 onward and has been patched in 6.16.4 and 6.17. CVE-2025-39777 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-39777?

CVE-2025-39777 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-2025-39777?

Yes — CVE-2025-39777 has been patched. Fixed versions include 6.16.4 and 6.17. If you are running Linux kernel 6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-39777 actively exploited?

No — CVE-2025-39777 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.