CVE-2026-53221

critical

Description

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.

References

https://git.kernel.org/stable/c/fc657ac0767c49839b3ef0b08dc0953ca30883f8

https://git.kernel.org/stable/c/f513f308cc4bdb4530d033431592ffbc29b7fca1

https://git.kernel.org/stable/c/c327fa4fca31415431202e063767a7ae342e19c6

https://git.kernel.org/stable/c/a5c0359f5cbc51a2e2b114d6041e0f3c73f903e9

https://git.kernel.org/stable/c/90fd4513315ca07da99cfd8549d3e553a7160f0d

https://git.kernel.org/stable/c/47fb3c2b4203556308e64354b3e78f2ce221d646

https://git.kernel.org/stable/c/2fc7bc087cc7085368263d9d37bfe9a0bddd6a2d

https://git.kernel.org/stable/c/2abfb19bbb81958714ad1d43ebeb65b30394184b

Details

Source: Mitre, NVD

Published: 2026-06-25

Updated: 2026-06-28

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.00184