Auth bypass in Masteriyo Lms – Online Course Builder For Elearning, & Education

CVE-2026-5167

The Masteriyo LMS – Online Course Builder for eLearning, LMS & Education plugin for WordPress is vulnerable to Authorization Bypass Through User-Controlled Key in versions up to and including 2.1.7. This is due to insufficient webhook signature verification in the handle_webhook() function. The webhook endpoint processes unauthenticated requests and only performs signature verification if both the webhook_secret setting is configured AND the HTTP_STRIPE_SIGNATURE header is present. Since webhook_secret defaults to an empty string, the webhook processes attacker-controlled JSON payloads without any verification. This makes it possible for unauthenticated attackers to send fake Stripe webhook events with arbitrary order_id values in the metadata, mark any order as completed without payment, and gain unauthorized access to paid course content.

Vulnerability class: IDOR (Insecure Direct Object Reference)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.005 (39.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 39.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-5167: held from 0.004 to 0.005.

EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-5167?
CVE-2026-5167 is a medium-severity vulnerability in Masteriyo Lms – Online Course Builder For Elearning, & Education, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 5.3/10. Published 2026-04-08.
How severe is CVE-2026-5167?
Medium severity. CVSS v3 base score is 5.3 out of 10.