# Masteriyo LMS – LMS Course Builder, Quizzes & Certificates <= 3.4.3 - Authenticated (Subscriber+) Missing Authorization to Course Progress Item Completion

- **ID:** WPSEC-2026-1776
- **Plugin:** Masteriyo LMS – LMS Course Builder, Quizzes & Certificates (`learning-management-system`), https://wordpress.org/plugins/learning-management-system/
- **Affected versions:** all versions before 3.5.0
- **Fixed in:** 3.5.0 (Update to 3.5.0 or later.)
- **Severity:** Medium 4.3 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N)
- **Weakness:** CWE-862
- **Usage among sites WPSec scans:** plugin Low, affected versions None seen (as of 2026-10-27)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/learning-management-system
- **Fix released:** 2026-10-26
- **Published:** 2026-10-27
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1776/

## Description

The Masteriyo LMS plugin for WordPress is vulnerable to unauthorized modification of data via the course progress items REST endpoint in all versions up to, and including, 3.4.3, due to the progress write permission check relying only on a filter that defaulted to allowing the request, with no check that a quiz completion is backed by a finished quiz attempt. This makes it possible for authenticated attackers, with Subscriber-level access and above, to mark quizzes as completed without taking them (for example by repointing an existing completed lesson progress row at a quiz), bypassing course completion requirements.

## References

- https://wpsec.com/vuln/WPSEC-2026-1776/
- https://plugins.svn.wordpress.org/learning-management-system/tags/3.5.0/
- https://wordpress.org/plugins/learning-management-system/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1776/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.