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CVE

CVE-2026-53221

ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()
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CVE

CVE-2026-53221

ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()

In the Linux kernel, the following vulnerability has been resolved:

ip6vti: fix incorrect tunnel matching in vti6tnl_lookup()

In vti6tnllookup(), 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->tnlsrl) prone to hash collisions.

The bug is that the fallback search loops in vti6tnllookup() were

missing checks to ensure that the candidate tunnel actually has

a wildcard address.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
9.8
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
C
H
U
0
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
C
H
U
-

Related Resources

No items found.

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, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53221.json, https://nvd.nist.gov/vuln/detail/CVE-2026-53221, https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Severity

9.8

CVSS Score
0
10

Basic Information

Base CVSS
9.8
EPSS Probability
0.00514%
EPSS Percentile
0.4173%
Introduced Version
fbe68ee87522f6eaa10f9076c0a7117e1613f2f7,3.19.0,5.11.0,5.16.0,6.2.0,6.7.0,6.13.0,6.19.0,0
Fix Available
a5c0359f5cbc51a2e2b114d6041e0f3c73f903e9,5.10.259,5.15.210,6.1.176,6.6.143,6.12.94,6.18.36,7.0.13,6.1.176-1,5.10.259-1,6.1.176-1~deb11u1,6.12.94-1,7.0.0-1010.10~24.04.1,7.0.0-29.29~24.04.2,7.0.0-1016.16~24.04.1,0:5.10.259-258.1043.amzn2,0:1.0-0.amzn2,0:5.15.210-148.245.amzn2,1:6.1.176-220.358.amzn2023,1:1.0-0.amzn2023,1:6.18.36-69.134.amzn2023,1:6.12.94-123.174.amzn2023,6.12.95-r0,6.18.38-r0,6.18.36-r0

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