CVE-2026-66631 in MC WooCommerce Wishlist Plugin
Summary
by MITRE • 09/17/2026
Administrator SQL Injection in MC Woocommerce Wishlist <= 1.9.21 versions.
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Analysis
by VulDB Data Team • 09/17/2026
The vulnerability identified as an administrator-level SQL injection flaw within the MC WooCommerce Wishlist plugin, specifically affecting versions up to and including 1.9.21, represents a critical security risk for WordPress-based e-commerce environments. This weakness stems from insufficient input validation and sanitization mechanisms when processing user-supplied data that is subsequently incorporated into database queries without proper escaping or parameterization. Although the vulnerability requires administrator privileges to exploit, it remains severe because administrative accounts are often targeted through social engineering, credential stuffing attacks, or cross-site scripting vectors that escalate privilege levels. The presence of this flaw indicates a fundamental failure in implementing secure coding practices regarding dynamic SQL construction, allowing an authenticated attacker with admin access to manipulate backend database operations beyond their intended scope.
From a technical perspective, the core issue lies in how the plugin handles parameters passed through HTTP requests associated with wishlist management features or related administrative endpoints. When these inputs are directly concatenated into SQL statements without adequate filtering against special characters such as single quotes, semicolons, or comment sequences, they enable an attacker to alter the logic of the database query. This can lead to unauthorized data retrieval from other tables within the same database schema, modification of existing records, or in severe cases with specific database configurations and stored procedures, remote code execution via techniques like out-of-band network interactions. The lack of prepared statements or consistent use of whitelisting for input values creates a predictable attack surface that automated scanners and manual penetration testers can reliably exploit to extract sensitive information such as user credentials, session tokens, or proprietary business data stored in the WordPress database.
The operational impact of this vulnerability extends beyond simple data exfiltration. An attacker leveraging this SQL injection could potentially dump the entire wp_users table to obtain hashed passwords for all site users, including other administrators and customers if their data is accessible through joins. This compromises the confidentiality and integrity of the application's user base. Furthermore, depending on the database engine version and configuration, techniques such as UNION-based or blind boolean-based SQL injection could allow an attacker to read arbitrary files from the server filesystem if file permissions are misconfigured, potentially leading to full system compromise. The existence of this flaw undermines trust in the e-commerce platform, risking financial loss through fraud, regulatory penalties under data protection laws like GDPR due to personal data exposure, and significant reputational damage associated with a publicized security breach.
To mitigate this risk, immediate action is required by updating the MC WooCommerce Wishlist plugin to version 1.9.22 or later where these input validation issues have been addressed. Developers must ensure that all future code changes adhere strictly to secure coding standards, specifically utilizing parameterized queries or prepared statements provided by the WordPress database abstraction layer ($wpdb) rather than direct SQL concatenation. Input sanitization should be enforced using functions like esc_sql() for data insertion and update operations, while output escaping with esc_html() or similar methods is necessary when displaying data back to users to prevent secondary vulnerabilities such as cross-site scripting. Additionally, implementing a Web Application Firewall can provide an additional layer of defense by detecting and blocking common SQL injection patterns in HTTP requests before they reach the application logic. Regular security audits and static code analysis tools should be integrated into the development lifecycle to identify similar flaws proactively across all custom plugins and themes used within the WordPress ecosystem.
This vulnerability aligns with CWE-89, which describes Improper Neutralization of Special Elements used in an SQL Command, commonly known as SQL Injection. It also maps to MITRE ATT&CK technique T1059.004, specifically PowerShell or command-line interface abuse if file read capabilities are leveraged for further exploitation steps such as downloading additional payloads. The requirement for administrator access places it within the context of privilege escalation scenarios where initial foothold is gained through other means, highlighting the importance of robust authentication controls and multi-factor authentication to protect administrative accounts from being compromised in the first place.