CVE-2026-53221CWE-20

CVE-2026-53221

Critical · published June 25, 2026

CVSS v3.1
9.8
EPSS
1%
Percentile
46.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00576 · 46.7th percentile
Weakness
CWE-20 · Improper Input Validation
Published
2026-06-25T13:16Z
Affected products (14)
ProductVersionsFixed in
linux/linux_kernel≥ 3.19, < 5.10.2595.10.259
linux/linux_kernel≥ 5.11, < 5.15.2105.15.210
linux/linux_kernel≥ 5.16, < 6.1.1766.1.176
linux/linux_kernel≥ 6.2, < 6.6.1436.6.143
linux/linux_kernel≥ 6.7, < 6.12.946.12.94
linux/linux_kernel≥ 6.13, < 6.18.366.18.36
linux/linux_kernel≥ 6.19, < 7.0.137.0.13
linux/linux_kernelall versions—
linux/linux_kernelall versions—
linux/linux_kernelall versions—
linux/linux_kernelall versions—
linux/linux_kernelall versions—
linux/linux_kernelall versions—
linux/linux_kernelall versions—
References (9)
EPSS history
Timeline
  • 25 JUN 08:39Z
    ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()
    cvelistv5