CVE-2026-31629
CVE-2026-31629 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-667.
Key facts
- Severity: High (CVSS 3.x base score 8.8)
- EPSS exploit prediction: 0% (13th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-25522
- Weakness: CWE-667
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-31629?
- 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.
- How severe is CVE-2026-31629?
- CVE-2026-31629 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2026-31629 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-31629?
- CVE-2026-31629 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2026-31629?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-31629 have an EU (EUVD) identifier?
- Yes. CVE-2026-31629 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-25522.
- When was CVE-2026-31629 published?
- CVE-2026-31629 was published on 2026-04-24 and last updated on 2026-06-17.
References
- https://git.kernel.org/stable/c/0eb1263a3b8c36418c9ba295c9ab3abed664edbf
- https://git.kernel.org/stable/c/2b5dd4632966c39da6ba74dbc8689b309065e82c
- https://git.kernel.org/stable/c/665315df9c3486cb213fc44d83cc8bcd47fe0d26
- https://git.kernel.org/stable/c/796e0cac058252d0ad34ebe288e6f7979b5fc9b2
- https://git.kernel.org/stable/c/8977fad2b3c6eefd414131168d597c5d1d5e1abf
- https://git.kernel.org/stable/c/9b49e2a4b8219a2fc5cebf94f4ec34e509aff8a6
- https://git.kernel.org/stable/c/aba4712e8f0381cd5d196534ce2ad082626a5ab6
- https://git.kernel.org/stable/c/b2a23529593d011fb433a3d711fc597ed6a6bd2f
- https://git.kernel.org/stable/c/ff3d9e8f7244293e303f7b6ef70774291c7c27e9
Affected products (1)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
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