{"id":"CVE-2026-18439","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-18439","generatedAt":"2026-10-28T01:47:19.871Z","title":"The 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…","description":"The 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.","published":"2026-09-22T08:16:39.000Z","lastModified":"2026-09-23T19:17:29.000Z","status":"Deferred","sourceIdentifier":"security@wordfence.com","cvss":{"version":"3.1","score":4.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N"},"cwe":["CWE-639"],"affected":[],"epss":{"score":0.00434,"percentile":0.37474,"date":"2026-10-26","history":[{"date":"2026-09-22","score":0.0025,"percentile":0.16696}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.43%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-22T08:16:39.000Z","detail":{"score":"4.3","severity":"MEDIUM","publishedAt":"2026-09-22T08:16:39.080Z"},"summary":"New CVE, medium severity (CVSS 4.3)."}],"references":[{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/3.9.10/classes/QuizBuilder.php#L156","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/3.9.10/classes/QuizBuilder.php#L291","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/3.9.10/classes/QuizBuilder.php#L423","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/3.9.10/classes/QuizBuilder.php#L430","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/3.9.10/classes/QuizBuilder.php#L781","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/4.0.3/classes/QuizBuilder.php#L156","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/4.0.3/classes/QuizBuilder.php#L291","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/4.0.3/classes/QuizBuilder.php#L423","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/4.0.3/classes/QuizBuilder.php#L430","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/4.0.3/classes/QuizBuilder.php#L781","source":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/changeset/3690454/tutor/tags/4.0.8/classes/QuizBuilder.php","source":"security@wordfence.com"},{"url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/6d07c82d-262a-4ac1-9ee5-7ef4d025f66f?source=cve","source":"security@wordfence.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-18439","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}