Auth bypass in Stylemix Masterstudy Lms WordPress Plugin – For Online Courses And Education

CVE-2026-5060

The MasterStudy LMS WordPress Plugin – for Online Courses and Education plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 3.7.14. This is due to the `stm_lms_delete_cover()` function lacking ownership validation on the `file_id` parameter before passing it to `wp_delete_attachment()`. This makes it possible for authenticated attackers, with Instructor-level access and above, to delete arbitrary attachments belonging to any user by enumerating sequential attachment IDs.

Vulnerability class: IDOR (Insecure Direct Object Reference)

EPSS: 0.002 (11.7th percentile) — read the EPSS interpretation.