CVE-2026-18439

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreHIGH confidence

Score 4.3 from GitHub Security Advisory published 2026-09-22. A secondary CVSS source baseline 4.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 4.3Exploit: None knownExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

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.

CVSS v3
4.3
EG Score
4.3MEDIUMhigh confidence
EG Risk
19
EG Risk 19/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity43% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.3%
EPSS %ILE
14th
KEV
Not listed

CISA SSVCTrack at every mission impact level.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 22, 2026

Last Modified

September 23, 2026

References (12)

Vendor Advisories for CVE-2026-18439(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 19× in last 7d / 37× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-04 23:21 UTCEPSS rescore
  2. 2026-10-04 12:36 UTCEG score recompute
  3. 2026-10-04 12:36 UTCGHSA enrichment
  4. 2026-10-03 14:25 UTCEPSS rescore
  5. 2026-10-03 13:15 UTCEG score recompute
  6. 2026-10-03 13:15 UTCGHSA enrichment
  7. 2026-10-02 13:54 UTCEG score recompute
  8. 2026-10-02 13:54 UTCGHSA enrichment
  9. 2026-10-01 19:49 UTCEPSS rescore
  10. 2026-10-01 14:32 UTCGHSA enrichment
  11. 2026-09-30 15:11 UTCEG score recompute
  12. 2026-09-30 15:11 UTCGHSA enrichment
  13. 2026-09-30 15:02 UTCEPSS rescore
  14. 2026-09-29 15:50 UTCEG score recompute
  15. 2026-09-29 15:50 UTCGHSA enrichment
  16. 2026-09-29 15:20 UTCEPSS rescore
  17. 2026-09-28 16:27 UTCEG score recompute
  18. 2026-09-28 16:27 UTCGHSA enrichment
  19. 2026-09-28 13:51 UTCEPSS rescore
  20. 2026-09-27 17:06 UTCEG score recompute
  21. 2026-09-27 17:05 UTCGHSA enrichment
  22. 2026-09-27 13:47 UTCEPSS rescore
  23. 2026-09-26 17:44 UTCEG score recompute
  24. 2026-09-26 17:44 UTCGHSA enrichment
  25. 2026-09-26 15:58 UTCEPSS rescore
Show 12 more
  1. 2026-09-25 18:19 UTCGHSA enrichment
  2. 2026-09-24 18:40 UTCEG score recompute
  3. 2026-09-24 18:40 UTCGHSA enrichment
  4. 2026-09-23 19:19 UTCEG score recompute
  5. 2026-09-23 19:19 UTCGHSA enrichment
  6. 2026-09-23 18:50 UTCEG score recompute
  7. 2026-09-23 18:50 UTCGHSA enrichment
  8. 2026-09-22 19:12 UTCEG score recompute
  9. 2026-09-22 19:12 UTCGHSA enrichment
  10. 2026-09-22 08:34 UTCEG score recompute
  11. 2026-09-22 07:51 UTCEG score recompute
  12. 2026-09-22 07:50 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-18439?
CVE-2026-18439 is a medium vulnerability published on September 22, 2026. 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 tutorquizbuildersave AJAX action due to missing validation that nested questionid, answerid, deletedquestionids[], and…
When was CVE-2026-18439 disclosed?
CVE-2026-18439 was first published on September 22, 2026, with the most recent update on September 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18439 actively exploited?
CVE-2026-18439 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (14th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-18439?
CVE-2026-18439 has a CVSS base score of 4.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-18439?
No fix for CVE-2026-18439 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-18439 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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