CVE-2026-40172

What it is

authentik is an open-source identity provider. In versions prior to 2025.12.5 and 2026.2.0-rc1 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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data tampering, service disruption.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-05-22 19:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-23 16:10 UTC Last updatedMost recent change to the record

Details

Published

2026-05-22 19:17 UTC

Last modified

2026-07-23 16:10 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-269 · Improper privilege management

Record status

Deferred

Attack profile CVSS 3.1 · 8.1

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

High