# WP Booking System <= 2.1.0.4 - Authenticated (Subscriber+) Missing Authorization to Booking Modification via AJAX Actions

- **ID:** WPSEC-2026-1378
- **Plugin:** WP Booking System – Booking Calendar (`wp-booking-system`), https://wordpress.org/plugins/wp-booking-system/
- **Affected versions:** all versions before 2.1.0.5
- **Fixed in:** 2.1.0.5 (Update to 2.1.0.5 or later.)
- **Severity:** Medium 5.4 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N)
- **Weakness:** CWE-862
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-10-21)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/wp-booking-system
- **Fix released:** 2026-10-19
- **Published:** 2026-10-21
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1378/

## Description

The WP Booking System plugin for WordPress is vulnerable to unauthorized access and modification of data via several booking management AJAX actions in all versions up to, and including, 2.1.0.4, due to a missing check that the current user may access the calendar a booking belongs to. The affected actions open booking details, email the customer, edit booking details and scheduled actions, and add or delete booking notes. This makes it possible for authenticated attackers, with Subscriber-level access and above, who have been given access to at least one calendar, to view and modify bookings that belong to calendars they are not allowed to access.

## References

- https://wpsec.com/vuln/WPSEC-2026-1378/
- https://plugins.svn.wordpress.org/wp-booking-system/tags/2.1.0.5/
- https://wordpress.org/plugins/wp-booking-system/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1378/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.