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.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.002 (6.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 6.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- Linux — versions c88d4c7b049e87998ac0a9f455aa545cc895ef92, 2.6.36, 0
- Linux Kernel — versions 2.6.36, 7.0
References
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
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.