CVE-2026-5060 in MasterStudy LMS Plugin
Summary
by MITRE • 07/29/2026
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.
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Analysis
by VulDB Data Team • 07/29/2026
The MasterStudy LMS WordPress plugin presents a critical security vulnerability classified as Insecure Direct Object Reference within versions up to and including 3.7.14. This flaw exists in the `stm_lms_delete_cover()` function which fails to implement proper ownership validation when processing the `file_id` parameter. The vulnerability stems from insufficient input sanitization and access control mechanisms that allow unauthorized manipulation of file references within the plugin's attachment management system. The issue specifically affects authenticated users who possess Instructor-level privileges or higher, creating a significant risk for malicious actors seeking to exploit this weakness.
The technical implementation of this vulnerability allows attackers to exploit sequential attachment ID enumeration techniques to identify and delete media files belonging to other users within the WordPress environment. When the `stm_lms_delete_cover()` function processes the `file_id` parameter without verifying that the requesting user owns the target attachment, it directly passes this identifier to WordPress's core `wp_delete_attachment()` function. This direct pass-through creates an opportunity for privilege escalation and unauthorized data destruction. The vulnerability operates at the application layer and can be exploited through crafted HTTP requests targeting the plugin's administrative endpoints.
The operational impact of this vulnerability extends beyond simple file deletion capabilities, as it enables attackers to disrupt educational content management systems and compromise user data integrity. An authenticated attacker with Instructor-level permissions can systematically enumerate attachment IDs to discover and remove media files associated with other users, potentially including course materials, student submissions, or institutional assets. This capability undermines the principle of least privilege and creates persistent risks for educational institutions relying on WordPress-based learning management systems. The vulnerability affects all users within the plugin's access hierarchy, making it particularly dangerous in environments where multiple instructors manage shared course content.
Security mitigations for this vulnerability should focus on implementing proper input validation and ownership verification mechanisms before processing file deletion requests. The recommended approach involves adding explicit permission checks that verify the requesting user's ownership of the target attachment ID before executing any deletion operations. This aligns with the CWE-284 principle of ensuring proper access control and authorization for sensitive operations within web applications. Organizations should immediately update to patched versions of the MasterStudy LMS plugin while implementing additional monitoring for unauthorized file deletion activities. The ATT&CK framework's T1078 technique for valid accounts and T1485 for data destruction emphasizes the importance of preventing unauthorized access to file management functions, particularly in educational environments where content integrity is paramount.