Vulnerability · Published May 7, 2026 · Assigned by GitHub_M
CVE-2026-41671Admidio: OIDC Token Introspection Endpoint Returns Active for All Tokens Without Validation
Medium 6.8
In plain English
A medium-severity improper authentication in admidio from Admidio. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Admidio is an open-source user management solution. Prior to version 5.0.9, the OIDC token introspection endpoint (/modules/sso/index.php/oidc/introspect) always returns {"active": true} for every request, regardless of whether a valid token is provided, whether the token is expired, revoked, or completely fabricated. The endpoint performs no authentication of the calling resource server and no validation of the submitted token. Any resource server that relies on this introspection endpoint to validate access tokens will accept all requests as authorized, enabling complete authentication bypass. Additionally, the OIDC token revocation endpoint (/oidc/revoke) returns {"revoked": true} without actually revoking any token, preventing resource servers from invalidating compromised credentials. 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-9xx5-cv6j-x533 |
Affected products (as reported)
Weakness: CWE-287 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N
References
- https://github.com/Admidio/admidio/security/advisories/GHSA-9xx5-cv6j-x533 x_refsource_CONFIRM
- https://github.com/Admidio/admidio/releases/tag/v5.0.9 x_refsource_MISC