What is CVE-2026-31639?

CVE-2026-31639 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 6.2 onward and patched in 6.6.135, 6.12.82, 6.18.23 and others. CVE-2026-31639 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-31639?

CVE-2026-31639 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-2026-31639?

Yes, CVE-2026-31639 has been patched. Fixed versions include 6.6.135, 6.12.82, 6.18.23 and others. If you are running Linux kernel 6.2 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-31639 actively exploited?

CVE-2026-31639 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-31639

Medium

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix key reference count leak from call->key When creating a client call in rxrpc_alloc_client_call(), the code obtains a reference to the key. This is never cleaned up and gets leaked when the call is destroyed. Fix this by freeing call->key in rxrpc_destroy_call(). Before the patch, it shows the key reference counter elevated: $ cat /proc/keys | grep afs@54321 1bffe9cd I--Q--i 8053480 4169w 3b010000 1000 1000 rxrpc afs@54321: ka $ After the patch, the invalidated key is removed when the code exits: $ cat /proc/keys | grep afs@54321 $

Package Linux Kernel

Published 2026-04-24

Last modified 2026-04-27

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 6.2 and later are affected. Fixed in 6.6.135, 6.12.82, 6.18.23, 6.19.13, 7.0 and their respective stable series.

Affected from

≥ 6.2

Fixed in

✓ 6.6.135 6.6.x ✓ 6.12.82 6.12.x ✓ 6.18.23 6.18.x ✓ 6.19.13 6.19.x ✓ 7.0

References

The following references provide additional information about CVE-2026-31639 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/2e6ef713b1598f6acd7f302fa6b12b6731c89914
Patch
Kernel patch commit
https://git.kernel.org/stable/c/978108902ee4ef2b348ff7ec36ad014dc5bc6dc6
Patch
Kernel patch commit
https://git.kernel.org/stable/c/d666540d217e8d420544ebdfbadeedd623562733
Patch

5 patch commits total View all on NVD

Details

CVE ID CVE-2026-31639

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-04-24

Modified 2026-04-27

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-31639?

CVE-2026-31639 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.2 onward and has been patched in 6.6.135, 6.12.82, 6.18.23 and others. CVE-2026-31639 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-31639?

CVE-2026-31639 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-2026-31639?

Yes — CVE-2026-31639 has been patched. Fixed versions include 6.6.135, 6.12.82, 6.18.23 and others. If you are running Linux kernel 6.2 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-31639 actively exploited?

No — CVE-2026-31639 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.