8.1

CVE-2026-40172: authentik: Privilege Escalation via User PATCH: Superuser Group Assignment Bypasses enable_group_superuser

Deferred
Published 22-05-2026Last modified 22-05-2026

Vulnerability summary

CVE-2026-40172 is a high (CVSS 8.1) Improper Privilege Management vulnerability in goauthentik authentik. EPSS estimates a 0.55% chance of exploitation in the next 30 days, higher than 45.8% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 8.1, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
8.1/10
010
High · v3.1 (CVE.org)
EPSS score
0.55%
0%100%
Low · -0.17 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 22-05-2026
    PublishedVulnerability first disclosed.
  2. 22-05-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.55%

Chance of exploitation in the next 30 days

Percentile

46%

Versus all other CVEs

30-day change

Decrease -0.17 pp

From 0.72% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Goauthentik1 product
  • authentik< 2025.12.5 | ≥ 2026.2.0-rc1, < 2026.2.3

1 vendor · 1 product

References

3 links