CVE-2026-31629

High

In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: add missing return after LLCP_CLOSED checks In nfc_llcp_recv_hdlc() and nfc_llcp_recv_disc(), when the socket state is LLCP_CLOSED, the code correctly calls release_sock() and nfc_llcp_sock_put() but fails to return. Execution falls through to the remainder of the function, which calls release_sock() and nfc_llcp_sock_put() again. This results in a double release_sock() and a refcount underflow via double nfc_llcp_sock_put(), leading to a use-after-free. Add the missing return statements after the LLCP_CLOSED branches in both functions to prevent the fall-through.

Package Linux Kernel
Published 2026-04-24
Last modified 2026-06-01
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

8.8

out of 10
High
Attack Vector
Adjacent
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness type

CWE-667

CVE-2026-31629 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 3.3 and later are affected. Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83, 6.18.24, 6.19.14, 7.0.1, 7.1-rc1 and their respective stable series.

Affected from
≥ 3.3
Fixed in
✓ 5.10.258 5.10.x ✓ 5.15.209 5.15.x ✓ 6.1.175 6.1.x ✓ 6.6.136 6.6.x ✓ 6.12.83 6.12.x ✓ 6.18.24 6.18.x ✓ 6.19.14 6.19.x ✓ 7.0.1 7.0.x ✓ 7.1-rc1

References

The following references provide additional information about CVE-2026-31629 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

9 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2026-31629?

    CVE-2026-31629 is a High severity Linux kernel vulnerability with a CVSS score of 8.8 out of 10 , classified as an Improper Locking flaw (CWE-667) . It affects Linux kernel versions from 3.3 onward and has been patched in 5.10.258, 5.15.209, 6.1.175 and others. CVE-2026-31629 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-31629?

    CVE-2026-31629 has a CVSS score of 8.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2026-31629?

    Yes — CVE-2026-31629 has been patched. Fixed versions include 5.10.258, 5.15.209, 6.1.175 and others. If you are running Linux kernel 3.3 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-31629 actively exploited?

    No — CVE-2026-31629 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Improper Locking (CWE-667)?

    The product does not properly acquire or release a lock, which can lead to unexpected behaviour. View CWE-667 on MITRE CWE →

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