Vulnerability · Published Apr 8, 2026 · Assigned by Wordfence

CVE-2026-5167Masteriyo LMS <= 2.1.7 - Unauthenticated Authorization Bypass to Arbitrary Order Completion via Stripe Webhook Endpoint

Medium 5.3

In plain English

A medium-severity authorization bypass via user-controlled key in Masteriyo LMS – Online Course Builder for eLearning, LMS & Education from masteriyo. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities).

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.4%top 66.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
masteriyo	Masteriyo LMS – Online Course Builder for eLearning, LMS & Education	0 – through 2.1.7

Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

In plain English

Official description

Affected products (as reported)

References