Booking and reservation plugins operate across a sensitive boundary between public form submission, calendar availability, customer-provided booking data, admin-side reservation management, and in some configurations external calendar synchronization. These plugins often process names, contact details, selected dates, time slots, service requests, event information, and notification templates, while also controlling whether a date or resource can be booked. A weakness in this class of plugin can lead to stored XSS through booking fields, unauthorized booking manipulation, information disclosure through request listings, CSRF against administrators, double-booking logic abuse, or unsafe synchronization behavior. Booking Calendar version 10.15.6 has successfully completed the CleanTalk Plugin Security Certification process and received PSC-2026-64650, confirming that the plugin was reviewed from a secure code perspective with attention to the most common exploitation paths for booking, appointment, reservation, calendar, and form-management plugins.
| Name of | Booking Calendar |
| Version | 10.15.6 |
| Active installations | 50,000+ |
| Description | Booking Calendar is a flexible WordPress booking plugin for appointments, reservations, rentals, and events. It allows site owners to display responsive availability calendars, create booking and inquiry forms, accept full-day or time-slot bookings, manage reservations from the WordPress admin panel, send email notifications, import Google Calendar events, and synchronize bookings with external services through .ics feeds. |
| Security | Successfully tested for: SQL Injection (SQLi) Cross-Site Scripting (XSS) – Stored & Reflected Cross-Site Request Forgery (CSRF) Authentication Vulnerabilities Authentication Bypass Exploits Privilege Escalation Buffer Overflow Denial-of-Service (DoS) vectors Data Leakage Vulnerabilities Insecure Dependency Usage Remote Code Execution (RCE) Risks Unauthorized File Access Insufficient Injection Protection Information Disclosure via Misconfigured Endpoints |
| CleanTalk Certification | Proudly earned the “Plugin Security Certification” (PSC) from CleanTalk, indicating adherence to stringent security standards. |
| Additional Information | Use Booking Calendar with confidence backed by the “Plugin Security Certification” (PSC). Always verify the latest plugin details and keep WordPress core and dependent components up to date. |
| Plugin Security Certification by CleanTalk |  |
| Logo of the plugin |  |
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Key Features
Booking Calendar provides a flexible booking system for WordPress sites that need to accept reservations, appointments, rentals, event registrations, service requests, or inquiry forms. The plugin allows administrators to publish booking calendars through blocks, widgets, or shortcodes, configure full-day and time-slot booking forms, manage submitted bookings from a modern admin panel, approve or decline reservations, and send email notifications to administrators and customers. It also includes availability management, prevention of double bookings, customizable booking form fields, drag-and-drop booking form building, multi-step form layouts, request and contact form use cases where the calendar can be optional, Google Calendar import, and synchronization with external services through .ics feeds. These capabilities matter from a security perspective because they touch several sensitive surfaces: front-end booking submissions, customer contact data, calendar availability logic, admin-side booking management, email template rendering, AJAX-based booking flows, and external calendar integration.
Security Assurance
The CleanTalk Plugin Security Certification evaluation for booking and reservation plugins focuses on the attack paths that are most relevant when public users submit structured data that later appears in administrative panels, emails, calendars, and booking records. In this class of software, common abuse patterns include attempts to inject JavaScript into booking fields or notification templates, manipulate calendar availability or booking status without authorization, abuse AJAX booking actions, enumerate private reservation data, exploit weak capability checks around booking management, or trigger CSRF against administrators who approve, edit, or delete reservations. Because booking plugins often store customer-provided data and may synchronize with external calendar systems, the review validates that public submissions are sanitized, administrative output is properly escaped, state-changing operations use nonce validation, and privileged booking-management actions are protected by appropriate roles and capability checks. Particular attention is paid to safe form handling, booking record access control, calendar availability integrity, email notification safety, AJAX request validation, and preventing synchronization or form-builder functionality from becoming injection, disclosure, or privilege boundary failures.
The plugin has been successfully tested for:
✅ Information Leakage Vulnerabilities
✅ SQL Injection Vulnerabilities
✅ Cross-Site Scripting (XSS) Attacks
✅ Cross-Site Request Forgery (CSRF) Attacks
✅ Authentication & Authentication Bypass Vulnerabilities
✅ Privilege Escalation Vulnerabilities
✅ Buffer Overflow Vulnerabilities
✅ Denial-of-Service (DoS) Vulnerabilities
✅ Data Leakage Vulnerabilities
✅ Insecure Dependencies
✅ Code Execution Vulnerabilities
✅ File Unauthorized Access Vulnerabilities
✅ Insufficient Injection Protection
Conclusion
With PSC-2026-64650, Booking Calendar version 10.15.6 demonstrates a strong baseline security posture for the workflows that matter most in booking and reservation systems: accepting booking submissions, managing availability, processing customer-provided form data, rendering booking information safely in wp-admin and notifications, protecting reservation-management actions, and maintaining integrity across calendar and synchronization workflows. This certification helps site owners and development teams reduce security and operational risk when deploying booking functionality that directly affects customer trust, business scheduling, and service availability. As a best practice, restrict who can manage bookings and plugin settings, review custom booking fields and email templates carefully, validate calendar synchronization configuration, monitor booking data retention requirements, and keep WordPress core, Booking Calendar, and related integration components up to date.
Note: The date and certification information may change over time. It is advisable to verify the latest details on the plugin developer’s website.