CVE-2026-40172
authentik: Privilege Escalation via User PATCH: Superuser Group Assignment Bypasses enable_group_superuser
Description
authentik is an open-source identity provider. In versions prior to 2025.12.5 and 2026.2.0 through 2026.2.2, the PATCH /api/v3/core/users/{pk}/ API allows a caller with change_user on a target user to assign arbitrary groups through UserSerializer, including groups with is_superuser=True, without requiring enable_group_superuser, leading to privilege escalation. This bypasses the stricter permission model enforced in group-management paths and enables delegated user-management permissions to escalate target users to administrator-equivalent privilege. Users with permissions to update groups or permissions to update users are able to add themselves or other users they have permissions on to users which have superuser permissions. This issue has been fixed in versions 22025.12.5 and 2026.2.3.
How to fix CVE-2026-40172
To remediate CVE-2026-40172, upgrade the affected package to a fixed version below.
- —upgrade to 2025.12.5 or later
Is CVE-2026-40172 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 2025.12.5, >= 2026.2.0, < 2026.2.3
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H |