DEBIAN-CVE-2026-53221

In the Linux kernel, the following vulnerability has been resolved:  ip6vti: fix incorrect tunnel matching in vti6tnllookup()  In vti6tnllookup(), when an exact match for a tunnel fails, the code falls back to searching for wildcard tunnels:  - Tunnels matching the packet's local address, with any remote address   wildcard remote).  - Tunnels matching the packet's remote address, with any local address   (wildcard local).  However, vti6 stores all these different types of tunnels in the same hash table (ip6n->tnlsrl) prone to hash collisions.  The bug is that the fallback search loops in vti6tnl_lookup() were missing checks to ensure that the candidate tunnel actually has a wildcard address.