CVE-2026-53221: ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()

Published Jun 25, 2026
·
Updated

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

Other sources

ip6vti: fix incorrect tunnel matching in vti6tnllookup()

Microsoft

Affected Software

18 affected componentsFixes available
Linux Linux kernel
Microsoft azl3 kernel 6.6.141.1-1<6.6.143.1-1
6.6.143.1-1
Linux Linux kernel>=3.19<5.10.259
Linux Linux kernel>=5.11<5.15.210
Linux Linux kernel>=5.16<6.1.176
Linux Linux kernel>=6.2<6.6.143
Linux Linux kernel>=6.7<6.12.94
Linux Linux kernel>=6.13<6.18.36
Linux Linux kernel>=6.19<7.0.13
Linux Linux kernel=7.1-rc1
Linux Linux kernel=7.1-rc2
Linux Linux kernel=7.1-rc3
Linux Linux kernel=7.1-rc4
Linux Linux kernel=7.1-rc5
Linux Linux kernel=7.1-rc6
Linux Linux kernel=7.1-rc7
debian/linux<=5.10.223-1
5.10.262-16.1.176-16.1.180-16.12.94-16.12.101-17.1.8-27.1.9-1
debian/linux-6.1
6.1.180-1~deb11u1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.6.143.1-1
  2. Upgrade

    Upgrade debian/linux to a version that resolves this vulnerability.

    Fixed in 5.10.262-1Fixed in 6.1.176-1Fixed in 6.1.180-1Fixed in 6.12.94-1Fixed in 6.12.101-1Fixed in 7.1.8-2Fixed in 7.1.9-1
  3. Upgrade

    Upgrade debian/linux-6.1 to a version that resolves this vulnerability.

    Fixed in 6.1.180-1~deb11u1

Event History

Jun 25, 2026
CVE Published
via MITRE·08:39 AM
Data Sourced
via MITRE·08:39 AM
DescriptionSeverity
Data Sourced
via NVD·09:16 AM
RemedyDescriptionSeverityAffected Software
Jun 27, 2026
Data Sourced
via Microsoft·08:18 AM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·08:18 AM
DescriptionSeverity
Aug 13, 2026
Data Sourced
via Launchpad·08:41 PM
Description
Aug 19, 2026
Data Sourced
via Ubuntu·08:45 PM
RemedyDescriptionSeverityAffected Software
Aug 22, 2026
Data Sourced
via Debian·08:49 PM
DescriptionAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2026-53221?

CVE-2026-53221 has a critical severity rating of 9.8.

2

What does CVE-2026-53221 affect?

CVE-2026-53221 affects the Linux kernel, specifically related to incorrect tunnel matching in the vti6_tnl_lookup() function.

3

How do I fix CVE-2026-53221?

To fix CVE-2026-53221, apply the available patch released by the Linux kernel.

4

What are the potential impacts of CVE-2026-53221?

CVE-2026-53221 could lead to unauthorized access to network traffic due to incorrect tunnel matching.

5

When was CVE-2026-53221 published?

CVE-2026-53221 was published on June 25, 2026.

Contact

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