CVE-2026-88849 in MasterStudy LMS Plugin
Summary
by MITRE • 10/23/2026
The MasterStudy LMS WordPress Plugin WordPress plugin before 3.7.55 does not verify that a user targeted through its student-enrolment feature has any relationship to the requesting instructor, allowing users with the Instructor role to overwrite the first name, last name and public display name of any registered user on the site, including administrators, enabling impersonation and phishing.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 10/23/2026
The vulnerability identified in MasterStudy LMS WordPress Plugin versions prior to 3.7.55 represents a critical failure in access control logic within the student-enrolment functionality. This flaw stems from an insufficient verification of relationships between users, specifically failing to ensure that a user targeted for enrolment actually has a valid association with the requesting instructor. In secure systems, operations involving sensitive data modification or role-based actions must strictly validate that the actor possesses the necessary permissions and contextual relationship to perform the action on the target resource. Here, the plugin allows any authenticated user holding the Instructor role to bypass these checks, treating all registered users as potential targets regardless of their actual enrollment status or administrative hierarchy. This lack of server-side authorization enforcement creates a significant security gap that undermines the integrity of the application's multi-tenant environment and its internal trust model.
The technical consequence of this flaw is the ability for an attacker with Instructor privileges to overwrite critical profile fields, including first name, last name, and public display name, for any registered user on the WordPress site. This capability extends beyond standard student accounts to include high-privilege users such as Administrators. By manipulating these identity attributes, an attacker can effectively impersonate other users within the system. The impact is not limited to data integrity but extends directly into social engineering vectors. An instructor could alter their own display name or that of a colleague to mimic trusted entities, thereby facilitating sophisticated phishing attacks against students, staff, and administrators who rely on these names for identification in communications and interface interactions.
From an industry standards perspective, this vulnerability aligns with CWE-269 Improper Privilege Assignment and CWE-862 Missing Authorization. The core issue is the absence of proper authorization checks before performing a state-changing operation on user data. Furthermore, the potential for impersonation links directly to MITRE ATT&CK technique T1078 Valid Accounts, where attackers use legitimate credentials to gain access and maintain persistence or move laterally within the environment. While the immediate exploitation involves modifying profile fields rather than executing code, the ability to alter identity information is a precursor to more severe attacks such as credential stuffing, account takeover via password reset manipulation if linked email addresses are also vulnerable, or targeted spear-phishing campaigns that exploit trust in institutional identities.
The operational impact of this vulnerability is substantial for organizations relying on WordPress and LMS integrations for education or corporate training. It compromises the authenticity of user interactions and erodes trust within the platform. Attackers can use modified names to send malicious emails from what appears to be a legitimate instructor account, potentially leading students to click on phishing links or download malware. Additionally, altering administrator profile information could disrupt administrative workflows or create confusion in audit logs if forensic analysis relies heavily on display names for attribution. The vulnerability affects the confidentiality and integrity of user data while indirectly impacting availability by degrading the reliability of communication channels within the learning management system.
Mitigation strategies must prioritize immediate patching to version 3.7.55 or later, where this authorization logic has been corrected. Administrators should also enforce strict role-based access control policies, ensuring that only necessary users are assigned the Instructor role and monitoring for unusual activity in user profile modifications. Implementing multi-factor authentication adds a layer of defense against account compromise but does not directly mitigate this specific server-side flaw. Regular security audits focusing on authorization checks in custom WordPress plugins are essential to prevent similar issues. Organizations should also consider implementing web application firewalls that can detect anomalous patterns in API requests related to user profile updates, providing an additional layer of monitoring and potential blocking for exploitation attempts until patches are applied.