Masteriyo LMS permits course-author stored XSS
Masteriyo LMS 1.18.0 through 3.3.x does not adequately sanitize and escape course settings before rendering them on a public page. A user with the plugin's course-author role can store script that executes for any visitor viewing the affected course, including an Administrator.
- Component
- Masteriyo LMS
- Plugin slug
masteriyo-lms- Affected
- 1.18.0 to < 3.4.0
- Safe version
3.4.0- Published
- Sep 05, 2026
This CVE was published Sep 05, 2026 and is one of 7 known issues for this plugin.
Update, patch or deactivate.
Update to Masteriyo LMS 3.4.0 or later, inspect course settings for malicious values, and invalidate privileged sessions if affected courses were viewed.
A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.
Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.
Technical description
The Masteriyo LMS WordPress plugin before 3.4.0 does not sanitise and escape some course settings before outputting them in a page available to all visitors, allowing users with a course-author role to perform Stored Cross-Site Scripting attacks that run in the session of anyone viewing the course, including a logged-in administrator.
CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H