CVE-2026-80636

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: revert ct extension genid infrastructure This infrastructure is not used anymore after moving ct timeout and helper to use datapath refcount to track object use. Revert commit c56716c69ce1 ("netfilter: extensions: introduce extension genid count") this patch disables all ct extensions (leading to NULL) for unconfirmed conntracks, when this is only targeted at ct helper and ct timeout. There is also codebase that dereferences the ct extension without checking for NULL which could lead to crash.

Is your site exposed to CVE-2026-80636?

Run a free security scan — no signup, results in seconds.

EPSS — Exploit Prediction

0.0017

Probability of exploitation

0.06%

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/35e21a4dccc5c255ba59ccfbfeb4629ed21da972 https://git.kernel.org/stable/c/61eab1d0237eb513fe73e391a5926ee70092c325 https://git.kernel.org/stable/c/6bba4846f196d081bf553391d12b5a73dcc48685 https://git.kernel.org/stable/c/a052a94bcc629acaecc2ce42a4af77f8fa399757 https://git.kernel.org/stable/c/d53eecbca16f056abba274075cb15120ab062518

Frequently Asked Questions

What is CVE-2026-80636? +

In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: revert ct extension genid infrastructure This infrastructure is not used anymore after moving ct timeout and helper to use datapath refcount to track object use. Revert commit c56716c69ce1 ("netfilter: extensions: introduce extension genid count") this patch disables all ct extensions (leading to NULL) for unconfirmed conntracks, when this is only targeted at ct helper and ct timeout. There is also codebase that dereferences the ct extension without checking for NULL which could lead to crash.

How do I check if I'm vulnerable to CVE-2026-80636? +

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.