Vulnerability · Published May 7, 2026 · Assigned by GitHub_M

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

High 8.2

In plain English

A high-severity security flaw in admidio from Admidio. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 9% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.2High

Exploit odds (30 days)0.2%top 91.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Packagist	admidio/admidio	5.0.9	GHSA-25cw-98hg-g3cg

Affected products (as reported)

Vendor	Product	Versions
Admidio	admidio	< 5.0.9

Weakness: CWE-347 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N

References

https://github.com/Admidio/admidio/security/advisories/GHSA-25cw-98hg-g3cg x_refsource_CONFIRM
https://github.com/Admidio/admidio/releases/tag/v5.0.9 x_refsource_MISC