CVE-2026-49111: Masteriyo LMS Privilege Escalation Flaw

CVE-2026-49111 Overview

CVE-2026-49111 is an Incorrect Privilege Assignment vulnerability [CWE-266] in the ThemeGrill Masteriyo Learning Management System (LMS) plugin for WordPress. The flaw affects all plugin versions from initial release through 2.2.0. Authenticated users with low-level access can escalate their privileges to higher roles within affected WordPress installations. Successful exploitation grants attackers elevated permissions that can compromise course content, student data, and site administration functions. The vulnerability carries network attack vector characteristics with low complexity and requires only low-privilege authentication.

Critical Impact
An authenticated attacker with minimal privileges can escalate to administrative-level access on WordPress sites running the Masteriyo LMS plugin, leading to full compromise of confidentiality, integrity, and availability.

Affected Products

ThemeGrill Masteriyo - LMS WordPress plugin
All versions from initial release through 2.2.0
WordPress installations using the Learning Management System plugin

Discovery Timeline

2026-06-15 - CVE CVE-2026-49111 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2026-49111

Vulnerability Analysis

The vulnerability stems from incorrect privilege assignment logic within the Masteriyo LMS plugin. The plugin assigns role capabilities without sufficient validation of the requesting user's authorization level. An authenticated user with a low-privilege account, such as a student or subscriber, can manipulate plugin functionality to obtain higher-level roles. This results in vertical privilege escalation [CWE-266] within the WordPress role-based access control system. The issue affects the plugin from initial release through version 2.2.0. Patchstack categorizes this as a privilege escalation vulnerability impacting WordPress sites that deploy the Learning Management System.

Root Cause

The root cause is improper enforcement of privilege boundaries in the plugin's user role assignment routines. The plugin fails to verify that the calling user has authorization to grant or modify the requested role. This design flaw permits low-privilege accounts to invoke operations that should be restricted to administrators. The CWE-266 classification confirms the underlying weakness as Incorrect Privilege Assignment.

Attack Vector

Attackers exploit the vulnerability over the network by sending crafted requests to vulnerable plugin endpoints from an authenticated session. The attack requires only low-privilege credentials, which are commonly obtainable through standard user registration on LMS sites that allow student enrollment. No user interaction from administrators is required. For exploitation details, refer to the Patchstack WordPress Vulnerability Report.

No public proof-of-concept code is currently available. The vulnerability mechanism involves invoking plugin endpoints that perform role modifications without verifying the caller's existing privilege level against the target role being assigned.

Detection Methods for CVE-2026-49111

Indicators of Compromise

Unexpected promotion of low-privilege WordPress users to administrator, editor, or masteriyo_instructor roles
Modifications to the wp_usermeta table where the wp_capabilities field changes for accounts that did not require role updates
Creation of new administrative accounts following authenticated requests to Masteriyo LMS endpoints
Anomalous POST requests to Masteriyo plugin REST API or admin-ajax handlers from low-privilege session cookies

Detection Strategies

Audit WordPress user role assignments and compare against expected role inventories on a recurring basis
Monitor web server logs for authenticated requests to Masteriyo LMS plugin endpoints originating from subscriber or student accounts
Enable WordPress audit logging plugins to track role changes, capability modifications, and user metadata updates
Review database change logs for unauthorized writes to wp_usermeta and wp_users tables

Monitoring Recommendations

Alert on any WordPress role escalation event where the source user does not hold administrator privileges
Track plugin version inventory across managed WordPress sites and flag installations running Masteriyo LMS 2.2.0 or earlier
Correlate user registration events with subsequent role change events to identify rapid escalation patterns
Monitor outbound traffic from WordPress servers for indicators of post-compromise activity such as webshell deployment

How to Mitigate CVE-2026-49111

Immediate Actions Required

Update the Masteriyo LMS plugin to a version later than 2.2.0 that contains the vendor's privilege assignment fix
Audit existing user accounts and revoke unauthorized role assignments, particularly any administrator or instructor roles granted to recently registered accounts
Disable open user registration temporarily if patching cannot be completed immediately
Rotate credentials for all administrative WordPress accounts after confirming no unauthorized access occurred

Patch Information

Review the Patchstack WordPress Vulnerability Report for vendor patch details and the fixed version. Apply the update through the WordPress plugin manager or via WP-CLI to all affected installations.

Workarounds

Restrict access to Masteriyo LMS plugin endpoints using a web application firewall rule that blocks role modification requests from non-administrator sessions
Disable the Masteriyo LMS plugin until the vendor patch is applied if the LMS functionality is non-essential
Enforce strict role validation through a custom WordPress filter that prevents non-administrators from triggering role assignment functions
Implement two-factor authentication on all administrative accounts to limit downstream impact of escalation

bash

# Update Masteriyo LMS plugin via WP-CLI
wp plugin update learning-management-system --version=<patched-version>

# Verify installed plugin version
wp plugin get learning-management-system --field=version

# Audit users with administrator capability
wp user list --role=administrator --fields=ID,user_login,user_registered