CVE-2026-2363: WP-Members Plugin SQLi Vulnerability

CVE-2026-2363 Overview

The WP-Members Membership Plugin for WordPress contains a SQL Injection vulnerability in the order_by attribute of the [wpmem_user_membership_posts] shortcode. This security flaw affects all versions up to and including 3.5.5.1 and allows authenticated attackers with Contributor-level access or above to inject malicious SQL queries into existing database queries. The vulnerability stems from insufficient escaping of user-supplied parameters and inadequate preparation of SQL queries, enabling attackers to extract sensitive information from the WordPress database.

Critical Impact

Authenticated attackers with Contributor-level permissions can exploit this SQL Injection to extract sensitive data from the database, potentially compromising user credentials, personal information, and other confidential site data.

Affected Products

• WP-Members Membership Plugin for WordPress versions up to and including 3.5.5.1

Discovery Timeline

• 2026-03-04 - CVE CVE-2026-2363 published to NVD
• 2026-03-04 - Last updated in NVD database

Technical Details for CVE-2026-2363

Vulnerability Analysis

This SQL Injection vulnerability (CWE-89) exists within the WP-Members Membership Plugin's shortcode processing functionality. The vulnerable code is located in class-wp-members-products.php, specifically around lines 490-496. When the [wpmem_user_membership_posts] shortcode is processed, the order_by attribute value is incorporated directly into the SQL query without proper sanitization or parameterization. This allows attackers to manipulate the query structure and append additional SQL commands to extract data they should not have access to.

The attack requires network access and low privileges (Contributor-level), making it accessible to any authenticated user with basic content creation permissions on a WordPress site using this plugin.

Root Cause

The root cause of this vulnerability is the failure to properly sanitize and escape user-supplied input in the order_by attribute before incorporating it into SQL queries. The plugin lacks sufficient use of WordPress's prepared statement mechanisms ($wpdb->prepare()) or proper validation of the parameter against an allowlist of acceptable column names. This allows arbitrary SQL code to be injected through the shortcode attribute.

Attack Vector

The attack is network-based and requires authentication with at least Contributor-level access to the WordPress site. An attacker can create or edit a post containing the [wpmem_user_membership_posts] shortcode with a malicious order_by attribute value. When the page is rendered, the injected SQL commands execute against the database.

For example, an attacker could craft a shortcode where the order_by parameter contains SQL syntax designed to extract data using techniques such as UNION-based injection, blind SQL injection, or time-based injection methods. The extracted data could include usernames, password hashes, email addresses, and other sensitive information stored in the WordPress database.

Technical details and the vulnerable code can be reviewed in the WordPress Plugin Trac references.

Detection Methods for CVE-2026-2363

Indicators of Compromise

• Unusual shortcode usage in posts or pages containing the [wpmem_user_membership_posts] shortcode with suspicious order_by attribute values
• Database query logs showing unexpected SQL syntax appended to membership-related queries
• Access patterns from Contributor-level accounts creating content with shortcodes they don't typically use
• Error logs indicating SQL syntax errors or database anomalies related to WP-Members functionality

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect SQL injection patterns in POST data and shortcode attributes
• Enable WordPress database query logging and monitor for anomalous query structures
• Configure SIEM alerts for SQL injection signatures targeting WordPress plugins
• Perform regular code audits of shortcode usage across posts and pages

Monitoring Recommendations

• Monitor authentication logs for unusual activity from Contributor-level accounts
• Track content creation and modification events, particularly those involving shortcodes
• Implement database activity monitoring to detect data exfiltration attempts
• Review web server logs for patterns consistent with SQL injection probing or exploitation

How to Mitigate CVE-2026-2363

Immediate Actions Required

• Update WP-Members Membership Plugin to version 3.5.6 or later immediately
• Review all posts and pages for suspicious shortcode usage, particularly [wpmem_user_membership_posts] with unusual order_by values
• Audit Contributor-level and above user accounts for unauthorized access or suspicious activity
• Consider temporarily disabling the plugin if immediate update is not possible

Patch Information

The vulnerability has been addressed in the WordPress Plugin Changeset #3468716. The fix implements proper input sanitization and prepared statements for the order_by parameter in the shortcode handler. Site administrators should update to the latest version of WP-Members through the WordPress plugin update mechanism. Additional details are available in the Wordfence Vulnerability Report.

Workarounds

• Remove or disable the [wpmem_user_membership_posts] shortcode functionality until the plugin can be updated
• Restrict Contributor-level access on sites using the vulnerable plugin version
• Implement a WAF rule to block requests containing the vulnerable shortcode with suspicious order_by values
• Consider using WordPress capability management to limit shortcode usage for lower-privileged users

# Temporarily disable WP-Members plugin via WP-CLI
wp plugin deactivate wp-members

# Update to patched version
wp plugin update wp-members

# Re-enable after update
wp plugin activate wp-members

# Verify the installed version
wp plugin get wp-members --field=version