CVE-2026-80636

Updated on 28 Aug 2026

Severity

5.5 Medium severity

Details

CVSS score
5.5

Overview

About vulnerability

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.

Details

Affected packages:
linux @ 4.19.0 (+3 more)

Fixes

KernelCare state

Live-patch status from KernelCare for each operating system.

Operating system Status Covered kernels
Ubuntu 24.04 Planned —
Ubuntu 24.04 AWS Planned —
Ubuntu 26.04 Will Not Fix —