CVE-2026-41669 HIGH

CVE-2026-41669: Admidio: SAML Signature Validation Result Ignored — Forged AuthnRequests and LogoutRequests Processed

Vendor Admidio
Product admidio
Weakness CWE-347
Published May 7, 2026
Last update May 7, 2026

CVSS base score

8.2/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality Low
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N

What the vulnerability does

01Description

Admidio is an open-source user management solution. Prior to version 5.0.9, the Admidio SAML Identity Provider implementation discards the return value of its validateSignature() method at both call sites (handleSSORequest() line 418 and handleSLORequest() line 613). The method returns error strings on failure rather than throwing exceptions, but the developer believed it would throw (per comments on lines 416 and 611). This means the smc_require_auth_signed configuration option is completely ineffective — unsigned or invalidly-signed SAML AuthnRequests and LogoutRequests are processed identically to properly signed ones. This issue has been patched in version 5.0.9.

Key dates

02Disclosure timeline

May 7, 2026 CVE published
May 7, 2026 Record updated