VulnerabilityDeferred

CVE-2026-6970

authd prior to version 0.6.4 contains a logic error in primary group ID assignment that can lead to local privilege escalation.

HIGH 7.3EPSS 0.11%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.11%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0: 7.3 HIGHCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.11% probability · 1th percentile
CISA KEV: Not listed
Weakness: CWE-842
Source: security@ubuntu.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.