CVE-2026-42730 Overview
CVE-2026-42730 is a blind SQL injection vulnerability in the Stylemix MasterStudy LMS plugin for WordPress. The flaw stems from improper neutralization of special elements in SQL commands [CWE-89]. It affects all versions of masterstudy-lms-learning-management-system from initial release through version 3.7.29. Authenticated attackers with low privileges can inject arbitrary SQL statements through vulnerable input parameters. The scope is changed, meaning the attacker can affect resources beyond the vulnerable component. Exploitation requires no user interaction and can be performed remotely over the network.
Critical Impact
Authenticated attackers can extract sensitive database contents — including user credentials, session tokens, and course data — from WordPress sites running MasterStudy LMS through 3.7.29.
Affected Products
- Stylemix MasterStudy LMS plugin (masterstudy-lms-learning-management-system)
- All versions from initial release through 3.7.29
- WordPress installations using the affected plugin
Discovery Timeline
- 2026-05-27 - CVE-2026-42730 published to NVD
- 2026-05-27 - Last updated in NVD database
Technical Details for CVE-2026-42730
Vulnerability Analysis
The MasterStudy LMS plugin fails to properly sanitize user-supplied input before incorporating it into SQL queries. This permits an authenticated attacker to inject malicious SQL syntax that the backend database executes. Because the vulnerability is blind, attackers infer query results through response timing or boolean-based differential responses rather than direct output. The changed scope indicates that injected SQL can affect database tables and resources outside the plugin's intended boundaries, including the core WordPress user table.
Root Cause
The root cause is improper neutralization of special elements used in an SQL command [CWE-89]. The plugin passes user-controlled parameters directly into SQL query strings without using parameterized queries or applying the WordPress $wpdb->prepare() API correctly. Attackers can break out of the intended query context by injecting characters such as single quotes, comments, and SQL keywords.
Attack Vector
Exploitation requires an authenticated session with at least subscriber-level privileges on the target WordPress site. The attacker submits crafted parameters to a vulnerable plugin endpoint over the network. By observing conditional response differences or time delays induced by SLEEP() payloads, the attacker extracts arbitrary data from the database one bit at a time. Common payload patterns include boolean-based blind injection (AND 1=1) and time-based blind injection (AND SLEEP(5)). See the Patchstack advisory for technical context.
Detection Methods for CVE-2026-42730
Indicators of Compromise
- Web server access logs containing SQL meta-characters (', --, UNION, SLEEP, BENCHMARK) in request parameters targeting MasterStudy LMS endpoints
- Anomalously long HTTP response times correlated with requests to plugin endpoints, indicating time-based blind injection
- Repeated requests from a single authenticated session iterating over numeric or alphabetic ranges in parameters
- Database query logs showing malformed or unusual queries originating from WordPress PHP processes
Detection Strategies
- Deploy a web application firewall rule set that flags SQL injection patterns in requests to /wp-admin/admin-ajax.php and MasterStudy LMS REST endpoints
- Enable MySQL general query logging temporarily and review queries containing concatenated user input from plugin functions
- Monitor authentication logs for low-privilege accounts generating high volumes of plugin API requests
Monitoring Recommendations
- Correlate authenticated user sessions with outbound database query patterns to surface enumeration behavior
- Alert on HTTP response time deviations greater than two standard deviations for MasterStudy LMS endpoints
- Track creation of new subscriber accounts followed by immediate API activity targeting the plugin
How to Mitigate CVE-2026-42730
Immediate Actions Required
- Upgrade MasterStudy LMS to a version newer than 3.7.29 as soon as the vendor publishes a fixed release
- Audit existing WordPress user accounts and remove unused subscriber-level or higher accounts
- Review recent database activity and authentication logs for signs of exploitation
- Restrict registration on WordPress sites where open registration is not required
Patch Information
Refer to the Patchstack vulnerability database entry for the latest patched version information. Apply the vendor-supplied update through the WordPress plugin manager or via WP-CLI. Validate the installed plugin version after the upgrade.
Workarounds
- Deploy a web application firewall with SQL injection signature coverage in front of the WordPress site
- Disable the MasterStudy LMS plugin until a patched version is installed if the site can tolerate downtime
- Restrict access to plugin endpoints using IP allowlisting for administrative networks where feasible
- Enforce the principle of least privilege and disable open user registration where not required
# Update MasterStudy LMS using WP-CLI once a fixed version is available
wp plugin update masterstudy-lms-learning-management-system
wp plugin get masterstudy-lms-learning-management-system --field=version
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
