Vulnerability · Published Apr 27, 2026 · Assigned by canonical
CVE-2026-6970authd Denial of Service and Local Privilege Escalation
High 7.3
In plain English
A high-severity security flaw in authd from Canonical. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 1% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/canonical/authd | 0.6.4 | GHSA-fg3j-5w9g-hmg7 |
| Go | github.com/canonical/authd | 0.6.4 | GO-2026-5361 |
| Ubuntu:26.04:LTS | authd | 0.6.1ubuntu0.1 | UBUNTU-CVE-2026-6970 |
Affected products (as reported)
Weakness: CWE-842 · Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N