CVE-2026-5167: masteriyo masteriyo lms – online course builder for elearning, lms & education

Vulnerability summary

CVE-2026-5167 is a medium (CVSS 5.3) vulnerability in masteriyo masteriyo lms – online course builder for elearning, lms & education. EPSS estimates a 0.49% chance of exploitation in the next 30 days, higher than 40.9% of scored vulnerabilities. Fixed in 2.1.8.

Timeline

1. 08-04-2026
   PublishedVulnerability first disclosed.
2. 08-04-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-639Authorization Bypass Through User-Controlled KeyThe system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.