authd <=0.6.3 LPE via GID misassignment bug
CVE-2026-6970 Published on April 27, 2026

authd Denial of Service and Local Privilege Escalation
authd prior to version 0.6.4 contains a logic error in primary group ID assignment that can lead to local privilege escalation. When a user's primary group ID (GID) differs from their UID, either because the account was created with authd prior to version 0.5.4 or because the primary group was manually changed via the `authctl group set-gid` command, and the user's identity provider record is updated, authd incorrectly resets the user's primary group ID to their UID upon next login. This causes newly created files and directories to be owned by the wrong group, causing denial of service issues, and potentially granting unintended access to other local users and allowing local privilege escalation.

Vendor Advisory NVD

Weakness Type

Placement of User into Incorrect Group

The software or the administrator places a user into an incorrect group. If the incorrect group has more access or privileges than the intended group, the user might be able to bypass intended security policy to access unexpected resources or perform unexpected actions. The access-control system might not be able to detect malicious usage of this group membership.


Affected Versions

Canonical authd: