{"id":"CVE-2026-18439","state":"PUBLISHED","title":"Tutor LMS <= 4.0.7 - Authenticated (Custom+) Insecure Direct Object Reference to Arbitrary Quiz Question/Answer Modification and Deletion via 'payload' Parameter","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.","publishedAt":"2026-09-22T07:41:12.011Z","updatedAt":"2026-09-23T18:46:53.858Z","severity":{"score":4.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","source":"Wordfence"},"assigner":"Wordfence","products":["themeum Tutor LMS – eLearning and online course solution"],"affected":[{"vendor":"themeum","product":"Tutor LMS – eLearning and online course solution","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"4.0.7","versionType":"semver"}]}],"references":["https://www.wordfence.com/threat-intel/vulnerabilities/id/6d07c82d-262a-4ac1-9ee5-7ef4d025f66f?source=cve","https://plugins.trac.wordpress.org/browser/tutor/tags/4.0.3/classes/QuizBuilder.php#L291","https://plugins.trac.wordpress.org/browser/tutor/tags/4.0.3/classes/QuizBuilder.php#L156","https://plugins.trac.wordpress.org/browser/tutor/tags/4.0.3/classes/QuizBuilder.php#L423","https://plugins.trac.wordpress.org/browser/tutor/tags/4.0.3/classes/QuizBuilder.php#L430","https://plugins.trac.wordpress.org/browser/tutor/tags/4.0.3/classes/QuizBuilder.php#L781","https://plugins.trac.wordpress.org/browser/tutor/tags/3.9.10/classes/QuizBuilder.php#L291","https://plugins.trac.wordpress.org/browser/tutor/tags/3.9.10/classes/QuizBuilder.php#L156","https://plugins.trac.wordpress.org/browser/tutor/tags/3.9.10/classes/QuizBuilder.php#L423","https://plugins.trac.wordpress.org/browser/tutor/tags/3.9.10/classes/QuizBuilder.php#L430","https://plugins.trac.wordpress.org/browser/tutor/tags/3.9.10/classes/QuizBuilder.php#L781","https://plugins.trac.wordpress.org/changeset/3690454/tutor/tags/4.0.8/classes/QuizBuilder.php"],"weaknesses":["CWE-639"],"ingestedAt":"2026-10-29T20:11:10.572Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/18xxx/CVE-2026-18439.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-18439","state":"PUBLISHED","datePublished":"2026-09-22T07:41:12.011Z","dateUpdated":"2026-09-23T18:46:53.858Z","assignerShortName":"Wordfence","assignerOrgId":"b15e7b5b-3da4-40ae-a43c-f7aa60e62599","dateReserved":"2026-07-30T20:23:23.648Z"},"containers":{"cna":{"title":"Tutor LMS <= 4.0.7 - Authenticated (Custom+) Insecure Direct Object Reference to Arbitrary Quiz Question/Answer Modification and Deletion via 'payload' Parameter","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"themeum","product":"Tutor LMS – eLearning and online course solution","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"4.0.7","versionType":"semver"}]}],"references":[{"url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/6d07c82d-262a-4ac1-9ee5-7ef4d025f66f?source=cve"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/4.0.3/classes/QuizBuilder.php#L291"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/4.0.3/classes/QuizBuilder.php#L156"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/4.0.3/classes/QuizBuilder.php#L423"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/4.0.3/classes/QuizBuilder.php#L430"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/4.0.3/classes/QuizBuilder.php#L781"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/3.9.10/classes/QuizBuilder.php#L291"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/3.9.10/classes/QuizBuilder.php#L156"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/3.9.10/classes/QuizBuilder.php#L423"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/3.9.10/classes/QuizBuilder.php#L430"},{"url":"https://plugins.trac.wordpress.org/browser/tutor/tags/3.9.10/classes/QuizBuilder.php#L781"},{"url":"https://plugins.trac.wordpress.org/changeset/3690454/tutor/tags/4.0.8/classes/QuizBuilder.php"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","baseScore":4.3,"baseSeverity":"MEDIUM"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-639","lang":"en","description":"CWE-639 Authorization Bypass Through User-Controlled Key","type":"CWE"}]}],"providerMetadata":{"shortName":"Wordfence","orgId":"b15e7b5b-3da4-40ae-a43c-f7aa60e62599","dateUpdated":"2026-09-22T07:41:12.011Z"},"credits":[{"lang":"en","type":"finder","value":"Nakul Chodha"}],"timeline":[{"time":"2026-07-30T20:38:30.000Z","lang":"en","value":"Vendor Notified"},{"time":"2026-09-21T18:52:22.000Z","lang":"en","value":"Disclosed"}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-18439","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-09-23T18:37:32.518219Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-23T18:46:53.858Z"}}]}}}