Improper Verification of Cryptographic Signature in authentik - CVE-2026-47201
Published: May 29, 2026
Vulnerability identifier: #VU132754
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-47201
CWE-ID: CWE-347
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Authentik Security Inc
Affected software:
authentik
authentik
Detailed vulnerability description
The vulnerability allows a remote user to authenticate as another federated user.
The vulnerability exists due to xml signature wrapping in SAML Source ACS endpoint when validating upstream SAML responses. A remote user can submit a crafted SAML response containing a forged assertion while reusing a valid signed assertion to authenticate as another federated user.
The issue affects deployments using a SAML Source for upstream SAML federation with signed assertions, or signed responses without signed assertions.
How to mitigate CVE-2026-47201
Install security update from vendor's website.