Vulnerability 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.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 3.19, < 5.10.259 |
References
- https://git.kernel.org/stable/c/2abfb19bbb81958714ad1d43ebeb65b30394184bPatch
- https://git.kernel.org/stable/c/2fc7bc087cc7085368263d9d37bfe9a0bddd6a2dPatch
- https://git.kernel.org/stable/c/47fb3c2b4203556308e64354b3e78f2ce221d646Patch
- https://git.kernel.org/stable/c/90fd4513315ca07da99cfd8549d3e553a7160f0dPatch
- https://git.kernel.org/stable/c/a5c0359f5cbc51a2e2b114d6041e0f3c73f903e9Patch
- https://git.kernel.org/stable/c/c327fa4fca31415431202e063767a7ae342e19c6Patch
- https://git.kernel.org/stable/c/f513f308cc4bdb4530d033431592ffbc29b7fca1Patch
- https://git.kernel.org/stable/c/fc657ac0767c49839b3ef0b08dc0953ca30883f8Patch
FAQ
What is CVE-2026-53221?
CVE-2026-53221 is a vulnerability with a CVSS score of 9.8 (CRITICAL). 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...
How severe is CVE-2026-53221?
CVE-2026-53221 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-53221?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.