Review reviewHigh

CVE-2026-47201

goauthentik authentik

authentik is an open-source identity provider. Prior to versions 2025.12.5, 2026.2.3, and 2026.5.1, authentik's SAML Source ACS endpoint is vulnerable to XML Signature Wrapping when validating upstream SAML responses. An attacker with any account at the upstream IdP can reuse a valid signed assertion to authenticate as another federated user. This issue has been patched in versions 2025.12.5, 2026.2.3, and 2026.5.1.

CVSS: 8.5
EPSS: 0.18%
CISA KEV: Not listed
Published: 2026.06.03

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.18%

Technical severityCVSS 8.5

Vulnerability overview

Affected product and versions

Product: goauthentik authentik
Affected versions: >= < 2025.12.5, >= < 2026.2.3, >= < 2026.5.1, < 2025.12.6, >= 2026.2.0 < 2026.2.4, >= 2026.5.0 < 2026.5.1
Fixed versions: 2025.12.6, 2026.2.4, 2026.5.1

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that goauthentik authentik and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
CWE: CWE-20, CWE-347