CVE-2026-41669 Admidio: SAML Signature Validation Result Ignored — Forged AuthnRequests and LogoutRequests Processed
Admidio ignores SAML signature validation results, allowing attackers to forge authentication and logout requests to bypass security controls.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-41669?
CVE-2026-41669 is a high-severity authentication bypass vulnerability in admidio, published on 7 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-347
Which versions are affected by CVE-2026-41669?
2 open source packages ship an affected version, including admidio/admidio.
| Package | Affected | Fixed in |
|---|---|---|
admidio/admidio Packagist | All versions | 5.0.9 |
admidio/admidio Packagist | All versions | 5.0.9 |
How do I fix CVE-2026-41669?
Upgrade admidio/admidio to 5.0.9 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-41669 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41669 exists.
Sources
Also known as GHSA-25cw-98hg-g3cg.