CVE-2026-6970 authd Denial of Service and Local Privilege Escalation
A logic error in authd allows local privilege escalation and denial of service by incorrectly resetting user group IDs during login.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-6970?
CVE-2026-6970 is a high-severity vulnerability in Canonical authd, published on 27 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
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.
Weakness: CWE-842
Which versions are affected by CVE-2026-6970?
3 open source packages ship an affected version, including github.com/canonical/authd.
| Package | Affected | Fixed in |
|---|---|---|
github.com/canonical/authd Go | From 0.6.0 | 0.6.4 |
github.com/canonical/authd Go | From 0.6.0 | 0.6.4 |
github.com/canonical/authd Go | From 0.6.0 | 0.6.4 |
How do I fix CVE-2026-6970?
Upgrade github.com/canonical/authd to 0.6.4 or later.
Is CVE-2026-6970 being exploited?
There is no known exploitation of CVE-2026-6970 in the wild and no public exploit code.
Sources
Also known as GHSA-fg3j-5w9g-hmg7, GO-2026-5361, UBUNTU-CVE-2026-6970, USN-8212-1.