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.

SeverityCritical
CVSS9.8
Exploit probability48. percentile0.6%
ProductLinux Kernel
PublishedJun 25, 2026
First seenJun 25, 2026

How to fix

Update
  • linux linux_kernel5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94, 6.18.36, 7.0.13 or later

Affected products

ProductAffected versionsFixed in
linux linux_kernel3.19 ≤ v < 5.10.259, 5.11 ≤ v < 5.15.210, 5.16 ≤ v < 6.1.176, 6.2 ≤ v < 6.6.143, 6.7 ≤ v < 6.12.94, 6.13 ≤ v < 6.18.36, 6.19 ≤ v < 7.0.13, 7.15.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94, 6.18.36, 7.0.13

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