Improper privilege management in authentik - CVE-2026-40172
Published: May 12, 2026
Vulnerability identifier: #VU131253
CSH Severity: Medium
CVSS v4: 7.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-40172
CWE-ID: CWE-269
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to escalate privileges.
The vulnerability exists due to improper privilege management in UserSerializer and the PATCH /api/v3/core/users/{pk}/ endpoint when processing user update requests that assign groups. A remote user can send a crafted PATCH request to assign a target user to groups with superuser privileges to escalate privileges.
The issue affects callers with change_user permission on a target user and can be used to add themselves or other permitted users to superuser groups without requiring enable_group_superuser.
Affected software
authentik
How to mitigate CVE-2026-40172
Install security update from vendor's website.
authentik - addressed in versions 2025.12.5, 2026.2.3