CVE-2026-53221
Status: AnalyzedCritical (9.8)—
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:
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.
Technical details traces, logs and code from the original report
- 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).
CVSS
- Version: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Base score: 9.8
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 0.51%
- Percentile among all scored CVEs: 42
- Score date: 10/4/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
🎯 ATT&CK techniques
How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.
- Exploitation
T1190Exploit Public-Facing Applicationinitial access60 %
Inferred by deterministic rules from the CVSS vector and CWE. Indicative only.
🛡️ ATT&CK mitigations that cover these techniques
Affected technologies (1)
CWEs
- NVD-CWE-noinfo
References
- https://git.kernel.org/stable/c/2abfb19bbb81958714ad1d43ebeb65b30394184b
- https://git.kernel.org/stable/c/2fc7bc087cc7085368263d9d37bfe9a0bddd6a2d
- https://git.kernel.org/stable/c/47fb3c2b4203556308e64354b3e78f2ce221d646
- https://git.kernel.org/stable/c/90fd4513315ca07da99cfd8549d3e553a7160f0d
- https://git.kernel.org/stable/c/a5c0359f5cbc51a2e2b114d6041e0f3c73f903e9
- https://git.kernel.org/stable/c/c327fa4fca31415431202e063767a7ae342e19c6
- https://git.kernel.org/stable/c/f513f308cc4bdb4530d033431592ffbc29b7fca1
- https://git.kernel.org/stable/c/fc657ac0767c49839b3ef0b08dc0953ca30883f8
Raw JSON (NVD)
Show
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