Summaryinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.6.129/6.12.76/6.18.17/6.19.7/7.0-rc3. Affected by this issue is some unknown functionality of the component apparmor. This manipulation causes an unknown weakness. The identification of this vulnerability is CVE-2026-23405. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.6.129/6.12.76/6.18.17/6.19.7/7.0-rc3. Affected by this vulnerability is some unknown processing of the component apparmor. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: apparmor: fix: limit the number of levels of policy namespaces Currently the number of policy namespaces is not bounded relying on the user namespace limit. However policy namespaces aren't strictly tied to user namespaces and it is possible to create them and nest them arbitrarily deep which can be used to exhaust system resource. Hard cap policy namespaces to the same depth as user namespaces.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-23405 since 01/13/2026. The exploitation appears to be difficult. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/01/2026).

Upgrading to version 6.6.130, 6.12.77, 6.18.18, 6.19.8 or 7.0-rc4 eliminates this vulnerability. Applying the patch 3f8699b3ee0c04b4b9bc27b82cd89a40e81e1d2e/853ce31ca72097d23991a06876a2ccb5cb64b603/d42b2b6bb77ca40ee34ab74ad79305840b5f315d/7b6495ead2c611647f6b11441a852324e3eb8616/306039414932c80f8420695a24d4fe10c84ccfb2 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-0950). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.6.129
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.12.46
• 6.12.47
• 6.12.48
• 6.12.49
• 6.12.50
• 6.12.51
• 6.12.52
• 6.12.53
• 6.12.54
• 6.12.55
• 6.12.56
• 6.12.57
• 6.12.58
• 6.12.59
• 6.12.60
• 6.12.61
• 6.12.62
• 6.12.63
• 6.12.64
• 6.12.65
• 6.12.66
• 6.12.67
• 6.12.68
• 6.12.69
• 6.12.70
• 6.12.71
• 6.12.72
• 6.12.73
• 6.12.74
• 6.12.75
• 6.12.76
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.19.0
• 6.19.1
• 6.19.2
• 6.19.3
• 6.19.4
• 6.19.5
• 6.19.6
• 6.19.7
• 7.0-rc1
• 7.0-rc2
• 7.0-rc3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Exploitinginfo

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