CVE-2026-41661

MEDIUM

Admidio: Reflected XSS in msg_window.php via Square Bracket to HTML Tag Conversion

Title source: cna
STIX 2.1

Description

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.

References (2)

Core 2
Core References
X_Refsource_Misc x_refsource_misc
https://github.com/Admidio/admidio/releases/tag/v5.0.9

Scores

CVSS v3 6.1
EPSS 0.0018
EPSS Percentile 7.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-79
Status published
Products (2)
admidio/admidio 0 - 5.0.9Packagist
Admidio/admidio < 5.0.9
Published May 07, 2026
Tracked Since May 07, 2026