CVE-2026-23405

apparmor: fix: limit the number of levels of policy namespaces

EPSS 0.2%

Vexday Risk Score

3Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS —EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

01 Apr 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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.

Affected products

Linux · Linux

References

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