medium4.9
CVE-2026-41657
Admidio Exposes Cross-Organization Member Data via Permission Check Mismatch in contacts_data.php
Impact
Admidio is an open-source user management solution. Prior to version 5.0.9, the contacts_data.php endpoint uses a weaker permission check (isAdministratorUsers(), requiring only rol_edit_user=true) than the frontend UI (contacts.php) which correctly requires the stronger isAdministrator() (requiring rol_administrator=true) and the contacts_show_all system setting. A user manager who is not a full administrator can directly request contacts_data.php?mem_show_filter=3 to retrieve all user records across all organizations in the Admidio instance, bypassing multi-tenant organization isolation. This issue has been patched in version 5.0.9.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | admidio/admidio | <= 5.0.8 | 5.0.9 |