CVE-2026-48952 is a CWE-79 (Improper Neutralization of Input During Web Page Generation) vulnerability in Joomla! CMS. It arises from a lack of proper escaping in the update list view of the com_installer component, enabling cross-site scripting attacks. The vulnerability is present in Joomla! CMS versions 4.0.0 through 5.4.6 and 6.0.0 through 6.1.1. The CVSS 4.0 base score is 5.9, indicating medium severity. No vendor advisory or patch is currently available, and no known exploits are reported in the wild.

Successful exploitation could allow an attacker with high privileges and user interaction to execute malicious scripts in the context of the affected Joomla! CMS web application. This could lead to actions such as session hijacking or unauthorized actions performed by the victim user. The impact is limited by the requirement for high privileges and user interaction.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, administrators should monitor Joomla! Project communications for updates. Applying strict input validation or output escaping workarounds in the affected component may reduce risk but are not official remedies.