CVE-2026-30927

Description

## Vulnerability 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. Line 47: `$getUserUuid = admFuncVariableIsValid($_GET, 'user_uuid', 'uuid', ...)` Line 424: `if ($event->possibleToParticipate() || $participants->isLeader($gCurrentUserId))` 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 `$user->getValue('usr_id')` (the target user from user_uuid) rather than the current user. ## Impact - Register unwilling users for events (potential harassment/spam) - Cancel other users' event participation - Manipulate event participant counts and comments - If events have participation limits, fill slots with unwanted registrations ## Fix For non-leader users, force `user_uuid` to the current user: ```php if (!$participants->isLeader($gCurrentUserId)) { $getUserUuid = $gCurrentUser->getValue('usr_uuid'); } ```

Affected packages (1)

• Packagist/admidio/admidiofrom 0, < 5.0.6

CVSS scores

References (5)

• ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-30927
• PATCHhttps://github.com/Admidio/admidio
• WEBhttps://github.com/Admidio/admidio/commit/e47f70cc3cbcdb39635fdbaaef02d19f604b8c3e
• WEBhttps://github.com/Admidio/admidio/issues/1985
• WEBhttps://github.com/Admidio/admidio/security/advisories/GHSA-7pfv-hr63-h7cw