Memory Management Flaw in Linux Kernel Networking Component

CVE-2026-63993

What is CVE-2026-63993?

A memory management vulnerability was identified in the Linux kernel related to the vxlan networking component. The flaw occurs due to improper handling of the skb->head values, specifically after the skb_tunnel_check_pmtu() function is called. This function changes the structure of the socket buffer, leading to a potential use-after-free condition if older ip_hdr values are incorrectly reused. The security issue can cause erratic kernel behavior and predictable memory accesses, which could be potentially exploited. It is advised to update to the latest version where this issue has been resolved.

References