Race condition in Linux kernel - CVE-2026-74662

Vulnerability details

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a race condition in inet_frag_create() and the fragment queue timer handling in net/ipv4/inet_fragment.c when processing fragmented packets with a zero or negative fragment timeout. A remote attacker can send specially crafted fragmented network traffic to cause a denial of service.

The issue occurs because the timer may run before the queue is published in the fqdir rhashtable, which can leave a stale hash node after reference handling becomes unbalanced.

Affected software

How to mitigate CVE-2026-74662

External References

• https://git.kernel.org/stable/c/653d7ddf6cba867777a3d14c4f83ace008c5ad13
• https://git.kernel.org/stable/c/928128865e43b197e30688dc1bc991592c97edcf
• https://git.kernel.org/stable/c/9f904dd3e455750e5d4ec9b2f134835811b85a2f

Related Security Bulletins

• Race condition in Linux kernel ipv4
• Debian update for linux