CVE-2026-41661: Admidio

Medium severity, CVSS 6.1. EPSS: 0.3% chance of exploitation in the next 30 days.

Admidio is an open-source user management solution. Prior to version 5.0.9, an unauthenticated attacker can execute arbitrary JavaScript in any Admidio user's browser through a reflected XSS in system/msg_window.php. The endpoint passes user input through htmlspecialchars(), which does not encode square brackets. A subsequent call to Language::prepareTextPlaceholders() converts those brackets into HTML angle brackets, producing executable markup. This issue has been patched in version 5.0.9.

Affected products

• Admidio Admidio: before 5.0.9 (fixed in 5.0.9)

Published 2026-05-07. Last modified 2026-06-17.