CVE-2026-18439 (GCVE-0-2026-18439)
Vulnerability from cvelistv5 – Published: 2026-09-22 07:41 – Updated: 2026-09-23 18:46
VLAI
EPSS
VEX
Title
Tutor LMS <= 4.0.7 - Authenticated (Custom+) Insecure Direct Object Reference to Arbitrary Quiz Question/Answer Modification and Deletion via 'payload' Parameter
Summary
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.
Severity
4.3 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-23 18:37 UTC
CWE
- CWE-639 - Authorization Bypass Through User-Controlled Key
Assigner
References
12 references
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| themeum | Tutor LMS – eLearning and online course solution |
Affected:
0 , ≤ 4.0.7
(semver)
|
guessed |
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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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