Critical severity · published Jun 25, 2026
CVE-2026-53221
ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()
9.8
CVSS
0.6%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 47% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
3.19 before 5.10.259; 5.11 before 5.15.210; 5.16 before 6.1.176; 6.2 before 6.6.143; 6.7 before 6.12.94; 6.13 before 6.18.36; +8 more · source: NVD
LI
Linux · Linux
fbe68ee87522f6eaa10f9076c0a7117e1613f2f7 before c327fa4fca31415431202e063767a7ae342e19c6; fbe68ee87522f6eaa10f9076c0a7117e1613f2f7 before fc657ac0767c49839b3ef0b08dc0953ca30883f8; fbe68ee87522f6eaa10f9076c0a7117e1613f2f7 before 47fb3c2b4203556308e64354b3e78f2ce221d646; fbe68ee87522f6eaa10f9076c0a7117e1613f2f7 before f513f308cc4bdb4530d033431592ffbc29b7fca1; fbe68ee87522f6eaa10f9076c0a7117e1613f2f7 before 90fd4513315ca07da99cfd8549d3e553a7160f0d; fbe68ee87522f6eaa10f9076c0a7117e1613f2f7 before 2abfb19bbb81958714ad1d43ebeb65b30394184b; +3 more · source: vendor
SS
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem · Siemens
0 · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-53221
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-53221
Patch
https://git.kernel.org/stable/c/2abfb19bbb81958714ad1d43ebeb65b30394184b
Patch
https://git.kernel.org/stable/c/2fc7bc087cc7085368263d9d37bfe9a0bddd6a2d
Patch
https://git.kernel.org/stable/c/47fb3c2b4203556308e64354b3e78f2ce221d646
Patch
https://git.kernel.org/stable/c/90fd4513315ca07da99cfd8549d3e553a7160f0d
Patch
https://git.kernel.org/stable/c/a5c0359f5cbc51a2e2b114d6041e0f3c73f903e9
Patch
https://git.kernel.org/stable/c/c327fa4fca31415431202e063767a7ae342e19c6
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