CVE-2026-0559: stylemix masterstudy lms wordpress plugin – for online courses and education Cross-site Scripting

Vulnerability summary

CVE-2026-0559 is a medium (CVSS 6.4) Cross-site Scripting vulnerability in stylemix masterstudy lms wordpress plugin – for online courses and education. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 13.1% of scored vulnerabilities. Fixed in 3.7.12.

Timeline

1. 14-02-2026
   PublishedVulnerability first disclosed.
2. 08-04-2026
   Last modifiedVulnerability information updated.

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.

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.