CVE-2026-13395 in Online Scheduling and Appointment Booking System Plugin
Summary
by MITRE • 07/30/2026
The Online Scheduling and Appointment Booking System WordPress plugin before 27.8 does not sanitize or properly cast a user-supplied parameter from its unauthenticated front-end booking requests before using it in a SQL query, allowing unauthenticated attackers to perform SQL injection attacks and extract sensitive data such as password hashes from the database.
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Analysis
by VulDB Data Team • 07/30/2026
The Online Scheduling and Appointment Booking System WordPress plugin version 27.8 and earlier contains a critical sql injection vulnerability that affects unauthenticated users. This flaw resides in the plugin's front-end booking request handling mechanism where user-supplied parameters are not properly sanitized or cast before being incorporated into database queries. The vulnerability allows attackers to manipulate input fields and inject malicious sql commands that bypass normal authentication checks, enabling unauthorized access to sensitive data including user password hashes stored within the wordpress database.
The technical implementation of this vulnerability stems from improper parameter handling in the plugin's booking submission process. When users submit appointment requests through the front-end interface, specific parameters are accepted without adequate validation or type casting. According to the common weakness enumeration standard CWE-89, this represents a classic sql injection flaw where untrusted data flows directly into sql command execution contexts. The vulnerability operates at the application layer and can be exploited by attackers who do not require any authentication credentials to initiate malicious requests against the vulnerable system.
The operational impact of this vulnerability extends beyond simple data theft to potentially enable complete system compromise. Attackers can leverage the sql injection to extract password hashes from user accounts, which may then be subjected to offline brute force attacks or used in credential reuse attacks across other systems. The unauthenticated nature of the exploit means that any user with access to the plugin's front-end interface can initiate these attacks without requiring login credentials, making the vulnerability particularly dangerous for wordpress installations that expose booking functionality to public users.
Security professionals should immediately recommend updating the Online Scheduling and Appointment Booking System plugin to version 27.8 or later where this sql injection vulnerability has been addressed through proper input sanitization and parameter binding mechanisms. The remediation process involves implementing prepared statements with proper parameter binding, which aligns with the defensive coding practices outlined in the mitre attack framework for preventing data exposure through sql injection techniques. Organizations should also conduct thorough penetration testing to identify any other instances of similar vulnerabilities within their wordpress installations and ensure that all plugins and themes undergo regular security auditing to maintain robust protection against evolving threats.