CVE-2026-19712 Masteriyo LMS < 2.3.3 - Instructor+ Stored XSS via Quiz Description
Instructors can inject malicious scripts into quiz descriptions, leading to stored XSS attacks against site visitors and administrators.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-19712?
CVE-2026-19712 is a medium-severity cross-site scripting vulnerability in Unknown Masteriyo LMS, published on 16 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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 DISALLOW_UNFILTERED_HTML, are not affected as the capability is not granted there.
Weakness: CWE-79
Which versions are affected by CVE-2026-19712?
How do I fix CVE-2026-19712?
No fix has been published for CVE-2026-19712 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-19712 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-19712 exists.
Sources
Also known as GHSA-9qrh-j6xc-w4qf.