Joomla! CMS versions 4.0.0-5.4.8 and 6.0.0-6.1.3 contain an XSS vulnerability (CWE-79) in the module list layout. The vulnerability occurs due to improper neutralization of input during web page generation, specifically failing to escape user-supplied values. This flaw can be exploited to execute arbitrary scripts in the context of the affected web application, potentially impacting confidentiality and integrity. The CVSS 4.0 vector indicates network attack vector, low attack complexity, no privileges required, partial user interaction, and high impact on confidentiality, integrity, and low impact on availability.

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary scripts in the context of the affected Joomla! CMS instance, potentially leading to information disclosure or manipulation of web content. The impact is rated medium severity with high confidentiality and integrity impact but low availability impact. There are no reports of active exploitation in the wild.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since no patch or official fix information is provided, users should monitor Joomla! Project advisories for updates. Until a fix is available, consider restricting access to the module list or applying input validation and output encoding as a temporary mitigation.