CVE-2026-23011

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

Description The Linux kernel contains a flaw in the ipv4/ip gre module related to the ipgre header() function. This issue can lead to kernel crashes when devices dynamically change their headroom or hard header length, potentially triggered by Multicast Listener Discovery (MLD) packets. The vulnerability was identified through syzbot testing, which found ways to crash the kernel by allocating an skb with insufficient reserve/headroom and then attaching an ipgre device. The fix involves making the ipgre header() function more robust, similar to a previous fix for the ip6 gre module.

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