CVE-2026-64518

Description

In the Linux kernel, the following vulnerability has been resolved: tcp: Fix out-of-bounds access for twsk in tcp_ao_established_key(). lockdep_sock_is_held() was added in tcp_ao_established_key() by the cited commit. It can be called from tcp_v[46]_timewait_ack() with twsk. Since it does not have sk->sk_lock, the lockdep annotation results in out-of-bound access. $ pahole -C tcp_timewait_sock vmlinux | grep size /* size: 288, cachelines: 5, members: 8 */ $ pahole -C sock vmlinux | grep sk_lock socket_lock_t sk_lock; /* 440 192 */ Let's not use lockdep_sock_is_held() for TCP_TIME_WAIT.

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EPSS — Exploit Prediction

0.0021

Probability of exploitation

0.11%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/03cb001ef87b3f8d859cf7f96329acf3d6235d29 https://git.kernel.org/stable/c/29cf64d128c94cf98d1c69d8b2962d39db5ff4c6 https://git.kernel.org/stable/c/510db031ba6eb40134f84c90ef963ea4b6dfb878 https://git.kernel.org/stable/c/87bb3e719042f0030a6dad39118c6a6b2a491ad9

Frequently Asked Questions

What is CVE-2026-64518? +

In the Linux kernel, the following vulnerability has been resolved: tcp: Fix out-of-bounds access for twsk in tcp_ao_established_key(). lockdep_sock_is_held() was added in tcp_ao_established_key() by the cited commit. It can be called from tcp_v[46]_timewait_ack() with twsk. Since it does not have sk->sk_lock, the lockdep annotation results in out-of-bound access. $ pahole -C tcp_timewait_sock vmlinux | grep size /* size: 288, cachelines: 5, members: 8 */ $ pahole -C sock vmlinux | grep sk_lock socket_lock_t sk_lock; /* 440 192 */ Let's not use lockdep_sock_is_held() for TCP_TIME_WAIT.

How do I check if I'm vulnerable to CVE-2026-64518? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.