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HIGH

CVE-2026-90231

CVSS v3

8.4

HIGH

EPSS Score

0.2 %

exploit probability, as of 2026-09-28

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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 unc

Technical details

Published
2026-09-17
Last Modified
2026-09-18

Frequently asked questions

What is CVE-2026-90231?

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 unc

Is CVE-2026-90231 actively exploited?

Active exploitation of CVE-2026-90231 has not been confirmed. Its EPSS score was 0.2% on 2026-09-28, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-90231?

CVE-2026-90231 has a CVSS v3 base score of 8.4 (HIGH severity).

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