Vulnerability in Linux

CVE-2026-23405

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.

EPSS: 0.002 (7.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

References

Frequently asked questions

What is CVE-2026-23405?
CVE-2026-23405 is a medium-severity vulnerability in Linux. CVSS score: 5.5/10. Published 2026-04-01.
How severe is CVE-2026-23405?
Medium severity. CVSS v3 base score is 5.5 out of 10.