XSS Vulnerability in Authentik Identity Provider by GoAuthentik
CVE-2026-42849

9.3CRITICAL

Key Information:

Vendor

Goauthentik

Status
Authentik
Vendor
CVE Published:
2 June 2026

What is CVE-2026-42849?

Authentik, an open-source identity provider, experienced a Cross-Site Scripting (XSS) vulnerability in the AutosubmitStage due to legacy browser compatibility features in its Simple Flow Executor (SFE) implementation. This exploit could allow unauthorized execution of scripts within the context of a user’s browser. Update to versions 2025.12.5 and 2026.2.3 to mitigate this security issue.

Affected Version(s)

authentik < 2025.12.5 < 2025.12.5

authentik < 2026.2.3 < 2026.2.3

References

https://github.com/goauthentik/authentik/security/advisor...
x_refsource_CONFIRM

CVSS V3.1

Score:
9.3
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.