CVE-2026-88847 in MasterStudy LMS Plugin
Summary
by MITRE • 09/24/2026
The MasterStudy LMS WordPress Plugin WordPress plugin before 3.7.50 does not verify that a user is enrolled in a course before recording lesson completions against it, allowing any authenticated user, such as a subscriber, to create course progress records for courses they have no access to.
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Analysis
by VulDB Data Team • 09/24/2026
The vulnerability identified within the MasterStudy LMS WordPress Plugin prior to version 3.7.50 represents a critical failure in business logic enforcement and authorization controls. This flaw stems from an insufficient verification mechanism that fails to validate whether an authenticated user holds valid enrollment status for a specific course before allowing actions related to lesson completion. In secure learning management systems, the recording of educational progress is strictly gated by access rights; however, this implementation allows any logged-in user with even minimal privileges, such as a subscriber role, to manipulate their academic records without proper authorization checks.
From a technical perspective, the core issue lies in the absence of server-side validation for course enrollment when processing requests to mark lessons or modules as complete. The application accepts input indicating lesson completion and updates the database accordingly based solely on the user's authentication token rather than verifying their entitlements against the specific course identifier provided in the request. This lack of object-level authorization control enables an attacker to bypass intended restrictions, effectively forging progress data for courses they have not purchased or registered for. Such a flaw aligns with CWE-862, which describes missing authorization checks, and is indicative of insecure direct object references where the system trusts client-supplied identifiers without validating associated permissions.
The operational impact of this vulnerability extends beyond simple record manipulation to potential integrity issues within educational platforms that rely on accurate progress tracking for certification or compliance purposes. An attacker can artificially inflate their course completion status, potentially gaining access to subsequent modules, certificates, or resources that are gated behind completed prerequisites. This undermines the trustworthiness of the learning platform's data and could lead to unauthorized access to advanced content if those sections are also protected by similar logic flaws. Furthermore, in environments where progress is tied to financial transactions or institutional accreditation, this manipulation constitutes a significant breach of data integrity.
This behavior maps directly to several techniques within the MITRE ATT&CK framework for enterprise security. Specifically, it relates to T1078 Valid Accounts, as exploitation requires valid authentication credentials, and T1136 Create Account, if an attacker creates multiple accounts to manipulate progress across different identities. More critically, it falls under T1542 Pre-Attack Phase Activities or more accurately within the execution phase as a form of privilege escalation through logic abuse rather than traditional code injection. The ability to alter state without proper authorization is also consistent with CWE-928, which addresses improper enforcement of mandatory access control in web applications.
Mitigation strategies must prioritize immediate patching to version 3.7.50 or later, where the developers have presumably implemented robust server-side checks for course enrollment status before processing lesson completion requests. In addition to updating the plugin, administrators should enforce strict role-based access controls and consider implementing additional validation layers that cross-reference user permissions with requested resources at every step of the interaction flow. Regular security audits focusing on business logic vulnerabilities are recommended, as these issues often evade traditional static analysis tools by functioning correctly within defined parameters but failing under unauthorized contexts.