CVE-2026-5167 — Vulnerability Advisory

Overview

Summary

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.

Risk profile

CVSS assessment

5.3 · M E D I U M

Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Attack vector: N E T W O R K
Complexity: L O W
Privileges: N O N E
User interaction: N O N E
Scope: U N C H A N G E D
Confidentiality: N O N E
Integrity: L O W
Availability: N O N E

Classification

Weaknesses

Authorization Bypass Through User-Controlled Key CWE-639

References

6 sources