CVE-2026-30927 — Admidio: Event participation IDOR - non-leaders can register other users for events via user_uuid parameter
Admidio is an open-source user management solution. Prior to 5.0.6, in modules/events/events_function.php, the event participation logic allows any user who can participate in a…
Published: 2026-03-09 · CVSS: 5.3 · CVSS 4.0
Admidio is an open-source user management solution. Prior to 5.0.6, in modules/events/events_function.php, the event participation logic allows any user who can participate in an event to register OTHER users by manipulating the user_uuid GET parameter. The condition uses || (OR), meaning if possibleToParticipate() returns true (event is open for participation), ANY user - not just leaders - can specify a different user_uuid and register/cancel participation for that user. The code then operates on $user->getValue('usr_id') (the target user from user_uuid) rather than the current user. This vulnerability is fixed in 5.0.6.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7