CVE-2026-4306: WP Job Portal SQL Injection Vulnerability

CVE-2026-4306 Overview

The WP Job Portal plugin for WordPress contains a SQL Injection vulnerability in the radius parameter affecting all versions up to and including 2.4.8. The vulnerability stems from insufficient escaping of user-supplied input and lack of proper preparation on existing SQL queries. This security flaw allows unauthenticated attackers to append malicious SQL queries to existing database queries, enabling extraction of sensitive information from the WordPress database.

Critical Impact

Unauthenticated attackers can exploit this SQL Injection vulnerability to extract sensitive data from the database, including user credentials, personal information, and potentially the entire database contents without requiring any authentication.

Affected Products

• WP Job Portal plugin for WordPress versions up to and including 2.4.8

Discovery Timeline

• 2026-03-23 - CVE CVE-2026-4306 published to NVD
• 2026-03-24 - Last updated in NVD database

Technical Details for CVE-2026-4306

Vulnerability Analysis

This vulnerability is classified as SQL Injection (CWE-89), a critical web application security flaw that occurs when user-controlled input is incorporated into SQL queries without proper sanitization. In the case of CVE-2026-4306, the radius parameter in the WP Job Portal plugin is directly incorporated into database queries without adequate escaping or parameterized query preparation. This allows attackers to manipulate the SQL query structure by injecting malicious SQL code through the radius parameter.

The vulnerability is particularly concerning because it can be exploited by unauthenticated users, meaning no login credentials or special permissions are required to launch an attack. The attack can be conducted over the network, making any WordPress site running the vulnerable plugin version a potential target.

Root Cause

The root cause of this vulnerability lies in improper input validation and insecure query construction within the plugin's codebase. Specifically, the vulnerability exists in the AJAX handler and job model components of the plugin. The affected code fails to properly escape user-supplied input before incorporating it into SQL queries and does not utilize WordPress's prepared statement functionality ($wpdb->prepare()) to safely parameterize query values.

According to the WordPress Job Portal Code and related model file, the radius parameter is processed without sufficient security measures, allowing SQL metacharacters to be interpreted as part of the query structure rather than as data values.

Attack Vector

The attack vector for this vulnerability is network-based, requiring no authentication or user interaction. An attacker can craft malicious HTTP requests containing specially crafted SQL injection payloads in the radius parameter. These requests are processed by the vulnerable AJAX endpoint, where the malicious input is incorporated into database queries.

The vulnerability allows attackers to perform various SQL injection techniques including UNION-based injection for data extraction, boolean-based blind injection for inferring database contents, and time-based blind injection when other methods are not feasible. Successful exploitation enables attackers to read sensitive database contents including WordPress user tables, custom plugin data, and potentially configuration information.

For detailed technical analysis and code references, see the Wordfence Vulnerability Report.

Detection Methods for CVE-2026-4306

Indicators of Compromise

• Unusual or malformed requests to WordPress AJAX endpoints containing SQL syntax in the radius parameter
• Web server logs showing requests with SQL keywords such as UNION, SELECT, OR 1=1, or comment sequences like -- in URL parameters
• Database query logs revealing unexpected or anomalous queries originating from the WP Job Portal plugin
• Error messages in application logs indicating SQL syntax errors or database exceptions

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block common SQL injection patterns in the radius parameter
• Deploy intrusion detection systems (IDS) with signatures for SQL injection attack patterns targeting WordPress installations
• Enable and monitor WordPress debug logging for database query errors or unusual query patterns
• Use security plugins that can detect and alert on SQL injection attempts in real-time

Monitoring Recommendations

• Configure centralized logging for all WordPress AJAX requests, particularly those involving job portal functionality
• Set up alerts for high volumes of requests containing potential SQL injection payloads
• Regularly review web server access logs for requests with unusual parameter values or encoding
• Monitor database performance for unexpected query patterns that may indicate data exfiltration attempts

How to Mitigate CVE-2026-4306

Immediate Actions Required

• Update the WP Job Portal plugin to version 2.4.9 or later immediately
• Review server and application logs for any signs of prior exploitation attempts
• Consider temporarily disabling the WP Job Portal plugin if immediate patching is not possible
• Implement WAF rules to block SQL injection attempts while planning the update

Patch Information

The vulnerability has been addressed in WP Job Portal version 2.4.9. The patch implements proper input sanitization and utilizes WordPress's prepared statement functionality to prevent SQL injection. The changes can be reviewed in the WordPress Job Portal Changelog. Site administrators should update to this version or later through the WordPress plugin management interface or by manually downloading the updated plugin from the WordPress plugin repository.

Workarounds

• Deploy a Web Application Firewall with rules specifically designed to detect and block SQL injection in WordPress plugin parameters
• Implement input validation at the web server level using ModSecurity or similar tools to reject requests containing SQL injection patterns
• Restrict access to WordPress AJAX endpoints using IP allowlisting if the job portal functionality is only needed for internal use
• Consider using a WordPress security plugin that provides virtual patching capabilities while awaiting official updates

# Example ModSecurity rule to block SQL injection in radius parameter
SecRule ARGS:radius "@detectSQLi" \
    "id:1001,\
    phase:2,\
    deny,\
    status:403,\
    log,\
    msg:'SQL Injection attempt detected in radius parameter',\
    tag:'application-multi',\
    tag:'language-multi',\
    tag:'platform-multi',\
    tag:'attack-sqli',\
    tag:'OWASP_CRS/WEB_ATTACK/SQL_INJECTION'"