[20260303] – Core – XSS vector in com_associations comparison view

• Project: Joomla!
• SubProject: CMS
• Impact: Moderate
• Severity: Moderate
• Probability: Low
• Versions: 4.0.0-5.4.3, 6.0.0-6.0.3
• Exploit type: XSS
• Reported Date: 2026-03-11
• Fixed Date: 2026-03-31
• CVE Number: CVE-2026-21631

Description

Lack of output escaping leads to a XSS vector in the multilingual associations component

Affected Installs

Joomla! CMS versions 4.0.0-5.4.3, 6.0.0-6.0.3

Solution

Upgrade to version 5.4.4 or 6.0.4

Contact

The JSST at the Joomla! Security Centre.

Reported By:  Shirsendu Mondal & Md Tanzimul Alam Fahim, UNC Pembroke