apparmor: fix unconfined user namespace restriction forced stack (CVE-2026-90231) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-90231

apparmor: fix unconfined user namespace restriction forced stack

Answer in brief

CVE-2026-90231 records a Unknown severity vulnerability in apparmor: fix unconfined user namespace restriction forced stack. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 17, 2026Updated Sep 17, 2026Source checked Sep 17, 2026First seen by HOL Sep 17, 2026Material review Sep 17, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=2d9da9b188b8cd3b579d7ef5ba5d334be9dd38fc <7d1099b86356df81c379159bfb8a598aaf83ce81 \|\| >=2d9da9b188b8cd3b579d7ef5ba5d334be9dd38fc <7da0bdf0610f6d35bbb061536a47fc41646306f0 \|\| >=2d9da9b188b8cd3b579d7ef5ba5d334be9dd38fc <08c2f7c8d4b1434cfae006f3daf4d1bce330b57b	7d1099b86356df81c379159bfb8a598aaf83ce81, 7da0bdf0610f6d35bbb061536a47fc41646306f0, 08c2f7c8d4b1434cfae006f3daf4d1bce330b57b
Linux/Linuxgeneric	6.7	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 7d1099b86356df81c379159bfb8a598aaf83ce81 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 17, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: apparmor: fix unconfined user namespace restriction forced stack If a task is already confined by a stack the unprivileged transition restriction on unconfined is not correctly, applied. This results in an escape if two transitions through an unconfined profile can be executed. Fix this by pushing the check into the per profile label build. The check will always be done against unconfined and result in a stack of just the unconfined component when necessary.

Quoted source text, attributed separately from HOL analysis.