What is CVE-2025-39942?

CVE-2025-39942 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 5.15 onward and patched in 6.1.154, 6.6.108, 6.12.49 and others. CVE-2025-39942 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-39942?

CVE-2025-39942 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-2025-39942?

Yes, CVE-2025-39942 has been patched. Fixed versions include 6.1.154, 6.6.108, 6.12.49 and others. If you are running Linux kernel 5.15 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-39942 actively exploited?

CVE-2025-39942 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2025-39942

Medium

In the Linux kernel, the following vulnerability has been resolved: ksmbd: smbdirect: verify remaining_data_length respects max_fragmented_recv_size This is inspired by the check for data_offset + data_length.

Package Linux Kernel

Published 2025-10-04

Last modified 2026-03-25

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 5.15 and later are affected. Fixed in 6.1.154, 6.6.108, 6.12.49, 6.16.9, 6.17 and their respective stable series.

Affected from

≥ 5.15

Fixed in

✓ 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-2025-39942 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/196a3a7676d726ee67621ea2bf3b7815ac2685b4
Patch
Kernel patch commit
https://git.kernel.org/stable/c/9644798294c7287e65a7b26e35aa6d2ce3345bcc
Patch
Kernel patch commit
https://git.kernel.org/stable/c/c64b915bb3d9339adcae5db4be2c35ffbef5e615
Patch

5 patch commits total View all on NVD

Details

CVE ID CVE-2025-39942

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2025-10-04

Modified 2026-03-25

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2025-39942?

CVE-2025-39942 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 5.15 onward and has been patched in 6.1.154, 6.6.108, 6.12.49 and others. CVE-2025-39942 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-39942?

CVE-2025-39942 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-2025-39942?

Yes — CVE-2025-39942 has been patched. Fixed versions include 6.1.154, 6.6.108, 6.12.49 and others. If you are running Linux kernel 5.15 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-39942 actively exploited?

No — CVE-2025-39942 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.