What is CVE-2026-31509?

CVE-2026-31509 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, classified as a Improper Locking flaw (CWE-667), affecting Linux kernel versions from 3.2 onward and patched in 5.10.253, 5.15.203, 6.1.168 and others. CVE-2026-31509 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-31509?

CVE-2026-31509 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-2026-31509?

Yes, CVE-2026-31509 has been patched. Fixed versions include 5.10.253, 5.15.203, 6.1.168 and others. If you are running Linux kernel 3.2 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-31509 actively exploited?

CVE-2026-31509 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Improper Locking (CWE-667)?

The product does not properly acquire or release a lock, which can lead to unexpected behaviour. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/667.html

CVE-2026-31509

Medium

In the Linux kernel, the following vulnerability has been resolved: nfc: nci: fix circular locking dependency in nci_close_device nci_close_device() flushes rx_wq and tx_wq while holding req_lock. This causes a circular locking dependency because nci_rx_work() running on rx_wq can end up taking req_lock too: nci_rx_work -> nci_rx_data_packet -> nci_data_exchange_complete -> __sk_destruct -> rawsock_destruct -> nfc_deactivate_target -> nci_deactivate_target -> nci_request -> mutex_lock(&ndev->req_lock) Move the flush of rx_wq after req_lock has been released. This should safe (I think) because NCI_UP has already been cleared and the transport is closed, so the work will see it and return -ENETDOWN. NIPA has been hitting this running the nci selftest with a debug kernel on roughly 4% of the runs.

Package Linux Kernel

Published 2026-04-22

Last modified 2026-04-28

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

Weakness type

CWE-667

CVE-2026-31509 is a Improper Locking vulnerability

What is Improper Locking?

The product does not properly acquire or release a lock, which can lead to unexpected behaviour. Learn more on MITRE CWE

Affected versions

Linux kernel versions 3.2 and later are affected. Fixed in 5.10.253, 5.15.203, 6.1.168, 6.6.131, 6.12.80, 6.18.21, 6.19.11, 7.0 and their respective stable series.

Affected from

≥ 3.2

Fixed in

✓ 5.10.253 5.10.x ✓ 5.15.203 5.15.x ✓ 6.1.168 6.1.x ✓ 6.6.131 6.6.x ✓ 6.12.80 6.12.x ✓ 6.18.21 6.18.x ✓ 6.19.11 6.19.x ✓ 7.0

References

8 total

Kernel Git
https://git.kernel.org/stable/c/09143c0e8f3b03517e6233aad42f45c794d8df8e

Patch
Kernel Git
https://git.kernel.org/stable/c/1edc12d2bbcb7a8d0f1088e6fccb9d8c01bb1289

Patch
Kernel Git
https://git.kernel.org/stable/c/4527025d440ce84bf56e75ce1df2e84cb8178616

Patch
Kernel Git
https://git.kernel.org/stable/c/5eef9ebec7f5738f12cadede3545c05b34bf5ac3

Patch
Kernel Git
https://git.kernel.org/stable/c/7ed00a3edc8597fe2333f524401e2889aa1b5edf

Patch

Showing 5 of 8 references View all on NVD

Details

CVE ID CVE-2026-31509

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-04-22

Modified 2026-04-28

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-31509?

CVE-2026-31509 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as an Improper Locking flaw (CWE-667) . It affects Linux kernel versions from 3.2 onward and has been patched in 5.10.253, 5.15.203, 6.1.168 and others. CVE-2026-31509 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-31509?

CVE-2026-31509 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-2026-31509?

Yes. CVE-2026-31509 has been patched. Fixed versions include 5.10.253, 5.15.203, 6.1.168 and others. If you are running Linux kernel 3.2 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-31509 actively exploited?

No. CVE-2026-31509 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.