CVE-2026-3523 in Apocalypse Meow Plugin
Summary
by MITRE • 03/05/2026
The Apocalypse Meow plugin for WordPress is vulnerable to SQL Injection via the 'type' parameter in all versions up to, and including, 22.1.0. This is due to a flawed logical operator in the type validation check on line 261 of ajax.php — the condition uses `&&` (AND) instead of `||` (OR), causing the `in_array()` validation to be short-circuited and never evaluated for any non-empty type value. Combined with `stripslashes_deep()` being called on line 101 which removes `wp_magic_quotes()` protection, attacker-controlled single quotes pass through unescaped into the SQL query on line 298. This makes it possible for authenticated attackers, with Administrator-level access and above, to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.
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Analysis
by VulDB Data Team • 03/06/2026
The CVE-2026-3523 vulnerability affects the Apocalypse Meow plugin for WordPress, representing a critical SQL injection flaw that undermines database security. This vulnerability exists in all plugin versions up to and including 22.1.0, making it a widespread concern for WordPress administrators who rely on this plugin for their website functionality. The flaw stems from a fundamental logical error in the input validation mechanism, specifically within the ajax.php file where the type parameter validation is handled. The vulnerability manifests through a simple yet devastating code logic error that fundamentally compromises the security of the validation process.
The technical root cause of this vulnerability lies in the flawed logical operator used within the type validation check on line 261 of the ajax.php file. The code employs the `&&` (AND) operator instead of the correct `||` (OR) operator, creating a condition that short-circuits the `in_array()` validation function. This logical error means that regardless of the input value provided, the validation check is never properly executed for any non-empty type parameter. The consequence of this flawed implementation is that legitimate input validation is completely bypassed, leaving the application vulnerable to malicious input manipulation. This type of vulnerability falls under the CWE-703 category, which encompasses improper check or handling of exceptional conditions, specifically in the context of input validation failures.
The operational impact of this vulnerability is particularly severe due to the combination of multiple security weaknesses that compound the risk. The plugin's code structure includes a call to `stripslashes_deep()` on line 101, which effectively neutralizes the `wp_magic_quotes()` protection that WordPress typically provides. This removal of protective measures creates a pathway for attacker-controlled single quotes to pass through the application unmodified and unescaped into the SQL query execution context on line 298. The combination of the logical operator error and the removal of quote escaping protection creates a perfect storm for SQL injection exploitation. The vulnerability specifically targets authenticated attackers with Administrator-level access or higher, making it particularly dangerous in environments where administrative privileges are compromised or where attackers can escalate their privileges through other means.
Authenticated attackers with administrative access can leverage this vulnerability to inject malicious SQL queries into existing database operations, potentially extracting sensitive information from the WordPress database. The attack vector is particularly concerning because it requires minimal privileges to exploit, as administrators already possess the necessary permissions to access the vulnerable plugin functionality. The vulnerability's impact extends beyond simple data extraction to potentially allow attackers to modify database content, escalate privileges, or even gain complete control over the WordPress installation. This type of attack aligns with the ATT&CK framework's privilege escalation techniques, specifically targeting the execution of malicious code through database manipulation. The vulnerability also demonstrates the importance of proper input validation and the dangers of improper logical operators in security-critical code sections.
The recommended mitigation strategies for this vulnerability include immediate plugin version updates to the latest secure release that addresses the logical operator error and restores proper input validation. Administrators should also implement additional security measures such as restricting administrative access through multi-factor authentication, monitoring for suspicious administrative activities, and conducting regular security audits of installed plugins. The vulnerability highlights the importance of thorough code review processes, particularly for security-critical functions that handle user input and database operations. Organizations should also consider implementing web application firewalls and database activity monitoring to detect and prevent exploitation attempts. Given the nature of the vulnerability, it is crucial for WordPress administrators to verify that all plugins are up to date and to maintain comprehensive backup strategies to ensure rapid recovery in case of successful exploitation.