CVE-2026-8441 in WP Review Slider Pro Plugin
Summary
by MITRE • 07/02/2026
The WP Review Slider Pro plugin for WordPress is vulnerable to SQL Injection via the 'notinstring' parameter of the wprp_load_more_revs AJAX action in versions up to, and including, 12.7.2. The parameter is read via $_POST['notinstring'] and passed through sanitize_text_field() — which strips HTML and whitespace but does not provide SQL safety. The value is then concatenated directly into a numeric/unquoted `AND id NOT IN (...)` clause and executed via $wpdb->get_results() without $wpdb->prepare() or intval() casting. Because the value sits in an unquoted numeric context, WordPress's wp_magic_quotes protection (which only escapes embedded quotes) is ineffective. The AJAX hook is registered via wp_ajax_nopriv_wprp_load_more_revs, and the required check_ajax_referer nonce is publicly available via wp_localize_script on any frontend page that renders the plugin shortcode, so an unauthenticated attacker who can reach a public page hosting the plugin can extract arbitrary data from the database via blind/time-based injection.
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Analysis
by VulDB Data Team • 07/02/2026
The WP Review Slider Pro plugin for WordPress presents a critical SQL injection vulnerability that undermines database security through improper input handling within its AJAX endpoint. This flaw exists in versions up to and including 12.7.2 where the 'notinstring' parameter of the wprp_load_more_revs AJAX action fails to implement proper sanitization techniques for database queries. The vulnerability stems from the plugin's reliance on sanitize_text_field() function which, while effective against HTML injection attempts, does not provide adequate protection against SQL injection attacks by failing to properly escape or cast values for database execution.
The technical implementation of this vulnerability occurs when the parameter $_POST['notinstring'] is read directly from user input and subsequently concatenated into a numeric context within an AND id NOT IN (...) clause. This approach bypasses WordPress's standard database query preparation mechanisms entirely, as the value passes through $wpdb->get_results() without proper $wpdb->prepare() usage or intval() casting that would normally ensure data type safety. The specific execution context places the parameter in an unquoted numeric position where wp_magic_quotes protection proves ineffective since this security feature only addresses quote escaping rather than numeric context injection.
The operational impact of this vulnerability extends beyond simple data extraction to encompass complete database compromise through blind and time-based SQL injection techniques. Attackers can leverage the publicly accessible wp_localize_script nonce mechanism that exposes the required check_ajax_referer validation token on any frontend page utilizing the plugin shortcode. This accessibility eliminates the need for authentication while maintaining the ability to perform systematic data harvesting through carefully crafted payloads that exploit the numeric context injection point.
Mitigation strategies must address both immediate remediation and long-term architectural improvements to prevent similar vulnerabilities in WordPress plugin development. The most effective immediate fix involves implementing proper parameter binding through $wpdb->prepare() or casting values using intval() before database execution, ensuring all user-provided input undergoes appropriate type validation regardless of its apparent context. Security practitioners should also implement comprehensive input validation at multiple layers including application-level sanitization and database query preparation techniques that align with industry standards such as those outlined in CWE-89 for SQL injection prevention.
The vulnerability demonstrates critical weaknesses in WordPress plugin security practices that align with ATT&CK framework techniques targeting credential access and data exposure through web application vulnerabilities. This flaw represents a prime example of how insufficient input validation combined with improper database query construction can create persistent security risks that affect thousands of websites simultaneously. Organizations should prioritize immediate patching of affected versions while implementing monitoring solutions that detect anomalous query patterns indicative of SQL injection attempts, particularly focusing on the specific numeric context patterns that characterize this vulnerability type.
The broader implications extend to WordPress ecosystem security where plugin developers must adopt more robust security practices including mandatory parameter validation, proper database abstraction layer usage, and comprehensive testing procedures that include security-oriented penetration testing methodologies. This vulnerability underscores the importance of following secure coding guidelines and demonstrates how seemingly minor implementation oversights can create substantial attack surface expansion for malicious actors targeting WordPress installations through third-party plugins.