23 Oct 2026 15:48:27 UTC
Tutor LMS <= 4.0.7 - Authenticated (Custom+) Insecure Direct Object Reference to Arbitrary Quiz Question/Answer Modification and Deletion via 'payload' Parameter
cve-program · CVE-2026-18439 · Published
CVE-2026-18439
Tutor LMS – eLearning and online course solution · Vulnerability
CVSS 3.1 4.3 MEDIUMCheck source for fixed versionsKEV status unknown
cve-program · CVE-2026-18439
PublishedThe Tutor LMS – eLearning and online course solution plugin for WordPress is vulnerable to Insecure Direct Object Reference in versions up to, and including, 4.0.7 via the tutor_quiz_builder_save AJAX action due to missing validation that nested question_id, answer_id, deleted_question_ids[], and deleted_answer_ids[] values in the submitted payload belong to a quiz/topic/course the requester is authorized to manage. The handler only validates the top-level course_id, topic_id, and (when supplied) payload['ID'], but the nested identifiers are passed straight into $wpdb->update/DELETE statements in QuizBuilder::save_questions(), QuizBuilder::save_question_answers(), and QuizBuilder::handle_delete(). This makes it possible for authenticated attackers, with Instructor-level access and above, to overwrite the content and re-parent arbitrary quiz questions/answers belonging to other instructors or administrators, and to delete arbitrary quiz question and answer rows.
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Exploitation and risk
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