What is CVE-2026-31391?

CVE-2026-31391 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 5.3 onward and patched in 5.10.253, 6.1.167, 6.6.130 and others. CVE-2026-31391 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-31391?

CVE-2026-31391 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-2026-31391?

Yes, CVE-2026-31391 has been patched. Fixed versions include 5.10.253, 6.1.167, 6.6.130 and others. If you are running Linux kernel 5.3 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-31391 actively exploited?

CVE-2026-31391 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-31391

Medium

In the Linux kernel, the following vulnerability has been resolved: crypto: atmel-sha204a - Fix OOM ->tfm_count leak If memory allocation fails, decrement ->tfm_count to avoid blocking future reads.

Package Linux Kernel

Published 2026-04-03

Last modified 2026-05-26

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 5.3 and later are affected. Fixed in 5.10.253, 6.1.167, 6.6.130, 6.12.78, 6.18.20, 6.19.10, 7.0 and their respective stable series.

Affected from

≥ 5.3

Fixed in

✓ 5.10.253 5.10.x ✓ 6.1.167 6.1.x ✓ 6.6.130 6.6.x ✓ 6.12.78 6.12.x ✓ 6.18.20 6.18.x ✓ 6.19.10 6.19.x ✓ 7.0

References

The following references provide additional information about CVE-2026-31391 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/1ab70c260cf16f931a728b2cb63fff5f38c814d8
Patch
Kernel patch commit
https://git.kernel.org/stable/c/2bfc83cee05f8b9604502df27d94e8e2b4a3dbf1
Patch
Kernel patch commit
https://git.kernel.org/stable/c/66ee9c1c3575b5d6afc340faca00fd40ed5b7ad9
Patch

7 patch commits total View all on NVD

Details

CVE ID CVE-2026-31391

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-04-03

Modified 2026-05-26

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-31391?

CVE-2026-31391 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 5.3 onward and has been patched in 5.10.253, 6.1.167, 6.6.130 and others. CVE-2026-31391 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-31391?

CVE-2026-31391 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-2026-31391?

Yes — CVE-2026-31391 has been patched. Fixed versions include 5.10.253, 6.1.167, 6.6.130 and others. If you are running Linux kernel 5.3 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-31391 actively exploited?

No — CVE-2026-31391 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.