Cyber Resilience

CVE-2026-53221

Critical

Published: 25 June 2026

Published
25 June 2026
Modified
30 June 2026
KEV Added
Patch
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0056 42.4th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-53221 is a critical-severity an unspecified weakness vulnerability in Kernel (inferred from references). Its CVSS base score is 9.8 (Critical).

Operationally, ranked at the 42.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

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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.

CWE(s)
None listed

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

Insufficient information to map techniques.
Confidence: LOW · MITRE ATT&CK Enterprise v19.0

Affected Assets

Kernel
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References