The LifterLMS – WP LMS for eLearning, Online Courses, & Quizzes plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'answer[]' parameter in all versions up to, and including, 10.3.2 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Exploitation requires the attacker to be enrolled as a student in a course containing a Content-type quiz question; the injected payload executes in the administrator's browser session during the normal grading workflow when 'Start a Review' is clicked on the affected attempt.