CVE-2026-23095

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description The Linux kernel’s GUE (Generic UDP Encapsulation) protocol handler contains a memory leak when processing packets with an inner IP protocol of 0. The issue occurs because gue udp recv() returns -guehdr->proto ctype for "resubmit" in ip protocol deliver rcu(), which only functions correctly with non-zero protocol numbers. This can lead to unreferenced objects and a memory leak. The issue was identified by syzbot, a kernel fuzzing tool, which generated a GUE packet triggering the leak. The root cause is related to handling packets with an inner protocol of 0, which is a valid number for IPv6 Hop-by-Hop Options, but not practical for encapsulation within GUE.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.