CVE-2026-53221

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.

Score

CVSS 3.1 9.8 Critical

Status

Modified - 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-06-25

Last modified

2026-10-19

Weaknesses

CWE-20

Affected products

• Linux Kernel (Linux)
• Simatic S7-1500 Tm Mfp - Gnulinux Subsystem (Siemens)

References

• https://git.kernel.org/stable/c/c327fa4fca31415431202e063767a7ae342e19c6
• https://git.kernel.org/stable/c/fc657ac0767c49839b3ef0b08dc0953ca30883f8
• https://git.kernel.org/stable/c/47fb3c2b4203556308e64354b3e78f2ce221d646
• https://git.kernel.org/stable/c/f513f308cc4bdb4530d033431592ffbc29b7fca1
• https://git.kernel.org/stable/c/90fd4513315ca07da99cfd8549d3e553a7160f0d
• https://git.kernel.org/stable/c/2abfb19bbb81958714ad1d43ebeb65b30394184b
• https://git.kernel.org/stable/c/2fc7bc087cc7085368263d9d37bfe9a0bddd6a2d
• https://git.kernel.org/stable/c/a5c0359f5cbc51a2e2b114d6041e0f3c73f903e9
• https://cert-portal.siemens.com/productcert/html/ssa-784472.html