CVE-2026-0559 Cross-site scripting in MasterStudy LMS WordPress Plugin – for Online Courses and Education
Authenticated contributors can inject arbitrary scripts via a shortcode, leading to code execution when other users view the page.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-0559?
CVE-2026-0559 is a medium-severity cross-site scripting vulnerability in stylemix MasterStudy LMS WordPress Plugin – for Online Courses and Education, published on 14 Feb 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
The MasterStudy LMS WordPress Plugin – for Online Courses and Education plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'stm_lms_courses_grid_display' shortcode in all versions up to, and including, 3.7.11 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
Weakness: CWE-79
Which versions are affected by CVE-2026-0559?
How do I fix CVE-2026-0559?
No fix has been published for CVE-2026-0559 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-2026-0559 being exploited?
There is no known exploitation of CVE-2026-0559 in the wild and no public exploit code.
Sources
Also known as GHSA-j7x7-gc84-q635.