CVE-2026-80738

bpf: Check sk_state before sk_protocol in bpf_tcp_*_syncookie

HIGH
7.3
CVSS Score
Published: September 3, 2026 at 08:21 AM UTC
Updated: October 30, 2026 at 01:20 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.3
Exploit prediction
EPSS 0.2%

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

399040847084a69f345e0a52fd62f04654e0fce35.2
Vendor states this is fixed in 23f682083aa3fbc0c49667818efd6979a8bc5ac2 (fixed)
Vendor states this is fixed in 31a420a822ff92e2090bd5d65efe8e34e2d6d9b8 (fixed)
Vendor states this is fixed in 5.2 (unaffected)
Vendor states this is fixed in 6.12.114 (unaffected)
Vendor states this is fixed in 6.18.57 (unaffected)
Vendor states this is fixed in 6.6.160 (unaffected)
Vendor states this is fixed in 7.1.9 (unaffected)
Vendor states this is fixed in 7.2 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

CVSS

7.3HIGHLinux
Vector?

Quick Info

StatusRECEIVED

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