CVE-2026-23405
Published: April 4, 2026Last modified: April 9, 2026
Description
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 5.5 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Vulnerable (6.1.164-r0) |
| 25 LTS | linux-lts | Fixed (6.12.80-r0) | |
| Stream | linux-lts | Fixed (6.12.80-r0) |
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