CVE-2026-8840
No known patch is available for this vulnerability.
The affected plugin has been removed from the WordPress.org directory, and no patched version is being distributed through the official directory. If you have the affected software installed, you should uninstall or replace it rather than wait for an update.
Description
The Booking calendar, Appointment Booking System plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 3.2.36. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for unauthenticated attackers to mark arbitrary reservations as paid or completed, cancel legitimate payments, auto-approve reservations, and trigger transactional booking emails by writing attacker-supplied payment status and transaction data directly into the payments table. The auto-approval of reservations is only triggered when the 'enable_psuccess_approval' site option is enabled, but payment status manipulation and email dispatch are exploitable regardless of that setting.
Affected products
1- Range: <=3.2.36
Patches
Vulnerability mechanics
References
9- plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.35/admin/controllers/Payment.phpnvd
- plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.35/admin/controllers/Payment.phpnvd
- plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.35/booking_calendar.phpnvd
- plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.35/booking_calendar.phpnvd
- plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.36/admin/controllers/Payment.phpnvd
- plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.36/admin/controllers/Payment.phpnvd
- plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.36/booking_calendar.phpnvd
- plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.36/booking_calendar.phpnvd
- www.wordfence.com/threat-intel/vulnerabilities/id/88409bb0-5cb0-4f63-b8f0-d72f54fa17b0nvd
News mentions
1- Wordfence Intelligence Weekly WordPress Vulnerability Report (August 10, 2026 to August 16, 2026)Wordfence Blog · Aug 21, 2026