CVE-2026-31629 nfc: llcp: add missing return after LLCP_CLOSED checks
A missing return statement in the Linux kernel NFC LLCP handler causes a use-after-free, potentially allowing local attackers to execute code or escalate privileges.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-31629?
CVE-2026-31629 is a high-severity use after free vulnerability in Linux kernel, published on 24 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-667
Which versions are affected by CVE-2026-31629?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-31629?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-31629 being exploited?
There is no known exploitation of CVE-2026-31629 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as A-499350302, ASB-A-499350302, AZL-83822, BELL-CVE-2026-31629, DEBIAN-CVE-2026-31629, GHSA-cfpg-q83x-6923 and 5 more.