PT-2026-52316 · Linux · Linux

Published 2026-06-25 · Updated 2026-06-25 · CVE-2026-53221

Mitre

In the Linux kernel, the following vulnerability has been resolved:

ip6 vti: fix incorrect tunnel matching in vti6 tnl lookup()

In vti6 tnl lookup(), 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->tnls r l) prone to hash collisions.

The bug is that the fallback search loops in vti6 tnl lookup() were missing checks to ensure that the candidate tunnel actually has a wildcard address.

Related Identifiers

CVE-2026-53221

Affected Products

Linux

References · 9

• https://nvd.nist.gov/vuln/detail/CVE-2026-53221 · Security Note
• https://git.kernel.org/stable/c/47fb3c2b4203556308e64354b3e78f2ce221d646 · Note
• https://git.kernel.org/stable/c/a5c0359f5cbc51a2e2b114d6041e0f3c73f903e9 · Note
• https://git.kernel.org/stable/c/f513f308cc4bdb4530d033431592ffbc29b7fca1 · Note
• https://git.kernel.org/stable/c/90fd4513315ca07da99cfd8549d3e553a7160f0d · Note
• https://git.kernel.org/stable/c/fc657ac0767c49839b3ef0b08dc0953ca30883f8 · Note
• https://git.kernel.org/stable/c/c327fa4fca31415431202e063767a7ae342e19c6 · Note
• https://git.kernel.org/stable/c/2fc7bc087cc7085368263d9d37bfe9a0bddd6a2d · Note
• https://git.kernel.org/stable/c/2abfb19bbb81958714ad1d43ebeb65b30394184b · Note