CVE-2026-41661
Admidio: Reflected XSS in msg_window.php via Square Bracket to HTML Tag Conversion
CVSS Score
6.1
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-79 |
| Vendor | admidio |
| Product | admidio |
| Published | May 7, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None
Affected Versions
Admidio / admidio
< 5.0.9