What is CVE-2025-21800?

CVE-2025-21800 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, affecting Linux kernel versions from 6.12 onward and patched in 6.12.13, 6.13.2 and 6.14. CVE-2025-21800 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-21800?

CVE-2025-21800 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2025-21800?

Yes, CVE-2025-21800 has been patched. Fixed versions include 6.12.13, 6.13.2 and 6.14. If you are running Linux kernel 6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-21800 actively exploited?

CVE-2025-21800 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2025-21800

High

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: HWS, fix definer's HWS_SET32 macro for negative offset When bit offset for HWS_SET32 macro is negative, UBSAN complains about the shift-out-of-bounds: UBSAN: shift-out-of-bounds in drivers/net/ethernet/mellanox/mlx5/core/steering/hws/definer.c:177:2 shift exponent -8 is negative

Package Linux Kernel

Published 2025-02-27

Last modified 2025-10-29

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Affected versions

Linux kernel versions 6.12 and later are affected. Fixed in 6.12.13, 6.13.2, 6.14 and their respective stable series.

Affected from

≥ 6.12

Fixed in

✓ 6.12.13 6.12.x ✓ 6.13.2 6.13.x ✓ 6.14

References

The following references provide additional information about CVE-2025-21800 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/69c676c0ded472713e6d1b3a456b3c4f52f66f0e
Patch
Kernel patch commit
https://git.kernel.org/stable/c/92cff996624c4757d5bbace3dfa3f1567ba94143
Patch
Kernel patch commit
https://git.kernel.org/stable/c/be482f1d10da781db9445d2753c1e3f1fd82babf
Patch

Details

CVE ID CVE-2025-21800

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2025-02-27

Modified 2025-10-29

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2025-21800?

CVE-2025-21800 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 6.12 onward and has been patched in 6.12.13, 6.13.2 and 6.14. CVE-2025-21800 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-21800?

CVE-2025-21800 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2025-21800?

Yes — CVE-2025-21800 has been patched. Fixed versions include 6.12.13, 6.13.2 and 6.14. If you are running Linux kernel 6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-21800 actively exploited?

No — CVE-2025-21800 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.