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.

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-gq27-fc8w-vcmp Admidio vulnerable to reflected XSS in msg_window.php via Square Bracket to HTML Tag Conversion
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 07 May 2026 05:45:00 +0000

Type Values Removed Values Added
First Time appeared Admidio
Admidio admidio
Vendors & Products Admidio
Admidio admidio

Thu, 07 May 2026 04:15:00 +0000

Type Values Removed Values Added
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.
Title Admidio: Reflected XSS in msg_window.php via Square Bracket to HTML Tag Conversion
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-07T02:59:34.649Z

Reserved: 2026-04-21T23:58:43.803Z

Link: CVE-2026-41661

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-07T04:16:29.920

Modified: 2026-05-07T04:16:29.920

Link: CVE-2026-41661

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-07T05:30:22Z

Weaknesses