Medium 5.5Published Apr 1, 2026

CVE-2026-23405apparmor: fix: limit the number of levels of policy namespaces

Updated under an hour ago (Oct 27, 2026, 4:30 AM ET)

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Exploited in the last 30 days

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.

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: May 11, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from c88d4c7b049e87998ac0a9f455aa545cc895ef92 before 6b396cc2f0365e684fc1d3547d18ef79fcee225d; from c88d4c7b049e87998ac0a9f455aa545cc895ef92 before 87d0cecc900e55d55fc4dbfb43ac93e269c7a5b3; from c88d4c7b049e87998ac0a9f455aa545cc895ef92 before b1226e37eb3754d389721c135db6107db94c7a72; from c88d4c7b049e87998ac0a9f455aa545cc895ef92 before 3f8699b3ee0c04b4b9bc27b82cd89a40e81e1d2e; from c88d4c7b049e87998ac0a9f455aa545cc895ef92 before 853ce31ca72097d23991a06876a2ccb5cb64b603; from c88d4c7b049e87998ac0a9f455aa545cc895ef92 before d42b2b6bb77ca40ee34ab74ad79305840b5f315d; from c88d4c7b049e87998ac0a9f455aa545cc895ef92 before 7b6495ead2c611647f6b11441a852324e3eb8616; from c88d4c7b049e87998ac0a9f455aa545cc895ef92 before 306039414932c80f8420695a24d4fe10c84ccfb2	CNA record
linux linux_kernel linux:linux_kernel	from 2.6.36.1 before 5.10.253; from 5.11 before 5.15.203; from 5.16 before 6.1.169; from 6.2 before 6.6.130; from 6.7 before 6.12.77; from 6.13 before 6.18.18; from 6.19 before 6.19.8; 2.6.36; and 7 more ranges	NVD

References

References

https://git.kernel.org/stable/c/6b396cc2f0365e684fc1d3547d18ef79fcee225d	patch
https://git.kernel.org/stable/c/87d0cecc900e55d55fc4dbfb43ac93e269c7a5b3	patch
https://git.kernel.org/stable/c/b1226e37eb3754d389721c135db6107db94c7a72	patch
https://git.kernel.org/stable/c/3f8699b3ee0c04b4b9bc27b82cd89a40e81e1d2e	patch
https://git.kernel.org/stable/c/853ce31ca72097d23991a06876a2ccb5cb64b603	patch
https://git.kernel.org/stable/c/d42b2b6bb77ca40ee34ab74ad79305840b5f315d	patch
https://git.kernel.org/stable/c/7b6495ead2c611647f6b11441a852324e3eb8616	patch
https://git.kernel.org/stable/c/306039414932c80f8420695a24d4fe10c84ccfb2	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.