Cross-site scripting (XSS) vulnerability in the URL downloader repository in repository/url/lib.php in Moodle through 2.3.11, 2.4.x before 2.4.10, 2.5.x before 2.5.6, and 2.6.x before 2.6.3 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.