Multiple cross-site scripting (XSS) vulnerabilities in the survey module in Moodle through 2.6.11, 2.7.x before 2.7.11, 2.8.x before 2.8.9, and 2.9.x before 2.9.3 allow remote authenticated users to inject arbitrary web script or HTML by leveraging the student role and entering a crafted survey answer.
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.