Cross-site scripting (XSS) vulnerability in mod/quiz/report/statistics/statistics_question_table.php in Moodle through 2.5.9, 2.6.x before 2.6.9, 2.7.x before 2.7.6, and 2.8.x before 2.8.4 allows remote authenticated users to inject arbitrary web script or HTML by leveraging the student role for a crafted quiz response.
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.