CVE-2026-19712: Masteriyo LMS < 2.3.3 - Instructor+ Stored XSS via Quiz Description
The Masteriyo LMS WordPress plugin before 2.3.3 does not sanitise and escape a quiz field before outputting it back in a page, and grants its instructor role the ability to store unfiltered HTML, allowing such users to perform Stored Cross-Site Scripting attacks against any visitor of the affected page, including administrators. This affects default single-site installations. Sites running multisite, or defining DISALLOWUNFILTEREDHTML, are not affected as the capability is not granted there.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Masteriyo LMS (WordPress plugin)to a version that resolves this vulnerability.Fixed in 2.3.3 - Configuration
If applicable to your environment, ensure DISALLOW_UNFILTERED_HTML is set such that unfiltered HTML is not granted (the advisory notes multisite or defining DISALLOW_UNFILTERED_HTML are not affected).
WordPress multisite / DISALLOW_UNFILTERED_HTML setting DISALLOW_UNFILTERED_HTML = enabled
Event History
Frequently Asked Questions
What is the severity of CVE-2026-19712?
CVE-2026-19712 has a risk score of 48, indicating a moderate severity level for the vulnerability.
What type of vulnerability is CVE-2026-19712?
CVE-2026-19712 is classified as a Stored Cross-Site Scripting (XSS) vulnerability in the Masteriyo LMS WordPress plugin.
How do I fix CVE-2026-19712?
To fix CVE-2026-19712, update the Masteriyo LMS plugin to version 2.3.3 or later.
Who is affected by CVE-2026-19712?
CVE-2026-19712 affects users with the instructor role in the Masteriyo LMS plugin prior to version 2.3.3.
What can attackers do with CVE-2026-19712?
Attackers can use CVE-2026-19712 to perform Stored Cross-Site Scripting attacks against visitors of the affected Masteriyo LMS sites.