High 7.3Published Sep 3, 2026

CVE-2026-80738bpf: Check sk_state before sk_protocol in bpf_tcp_*_syncookie

Updated under an hour ago (2026-10-19 07:23 UTC)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: bpf: Check sk_state before sk_protocol in bpf_tcp_*_syncookie bpf_tcp_gen_syncookie and bpf_tcp_check_syncookie accept a socket pointer 'sk' with argument type ARG_PTR_TO_BTF_ID_SOCK_COMMON. However, they access sk->sk_protocol without validating whether 'sk' represents a full socket. Fix this issue by checking sk->sk_state != TCP_LISTEN before inspecting sk->sk_protocol in both bpf_tcp_gen_syncookie and bpf_tcp_check_syncookie. Since mini-sockets are never in the TCP_LISTEN state, the condition short-circuits and prevents dereferencing fullsock-specific fields.

CVSS: 7.3 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Received
Record last updated: Oct 15, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	399040847084a69f345e0a52fd62f04654e0fce3 builds before 22c2169770ad3b3595690e51caac875178cf496d; 399040847084a69f345e0a52fd62f04654e0fce3 builds before 23f682083aa3fbc0c49667818efd6979a8bc5ac2; 399040847084a69f345e0a52fd62f04654e0fce3 builds before 31a420a822ff92e2090bd5d65efe8e34e2d6d9b8	CNA record

References

https://git.kernel.org/stable/c/22c2169770ad3b3595690e51caac875178cf496d
https://git.kernel.org/stable/c/23f682083aa3fbc0c49667818efd6979a8bc5ac2
https://git.kernel.org/stable/c/31a420a822ff92e2090bd5d65efe8e34e2d6d9b8

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.