admidio up to 5.0.8 contacts_data.php isAdministratorUsers authorization

Summaryinfo

A vulnerability was found in admidio up to 5.0.8. It has been rated as problematic. The impacted element is the function isAdministratorUsers of the file contacts_data.php. This manipulation causes authorization. This vulnerability appears as CVE-2026-41657. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in admidio up to 5.0.8. It has been declared as problematic. Affected by this vulnerability is the function isAdministratorUsers of the file contacts_data.php. The manipulation with an unknown input leads to a authorization vulnerability. The CWE definition for the vulnerability is CWE-863. The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions. As an impact it is known to affect confidentiality. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-41657 since 04/22/2026. The exploitation appears to be easy. The attack can be launched remotely. Additional levels of successful authentication are necessary for exploitation. Technical details are known, but no exploit is available.

By approaching the search of inurl:contacts_data.php it is possible to find vulnerable targets with Google Hacking.

Upgrading to version 5.0.9 eliminates this vulnerability. The upgrade is hosted for download at github.com.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• admidio

Version

• 5.0.0
• 5.0.1
• 5.0.2
• 5.0.3
• 5.0.4
• 5.0.5
• 5.0.6
• 5.0.7
• 5.0.8

Website

• Product: https://github.com/Admidio/admidio/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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