CVE-2026-30927 Admidio: Event participation IDOR - non-leaders can register other users for events via user_uuid parameter
Attackers can register or cancel other users for events by manipulating the user_uuid parameter, bypassing leader-only restrictions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-30927?
CVE-2026-30927 is a medium-severity missing authorization vulnerability in admidio, published on 9 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-639
Which versions are affected by CVE-2026-30927?
2 open source packages ship an affected version, including admidio/admidio. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
admidio/admidio Packagist | All versions | 5.0.6 |
admidio/admidio Packagist | All versions | 5.0.6 |
Products include Admidio Admidio.
How do I fix CVE-2026-30927?
Upgrade admidio/admidio to 5.0.6 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-30927 being exploited?
There is no known exploitation of CVE-2026-30927 in the wild and no public exploit code.
Other vulnerabilities in admidio
- CVE-2024-37906 Admidio has Blind SQL Injection in ecard_send.php
- CVE-2021-32630 Various
- CVE-2026-32817 Admidio is Missing Authorization and CSRF Protection on Document and Folder Deletion
- CVE-2024-38529 Admidio Vulnerable to RCE via Arbitrary File Upload in Message Attachment
- CVE-2026-32756 Admidio: Unrestricted File Upload via CSRF Token Validation Bypass in Documents & Files Module
Sources
Also known as GHSA-7pfv-hr63-h7cw.