Auth bypass in Wpdevart Booking Calendar, Appointment System

CVE-2026-8840

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.

Vulnerability class: Broken Access Control

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-8840?
CVE-2026-8840 is a medium-severity vulnerability in Wpdevart Booking Calendar, Appointment System, classified under Missing Authorization. CVSS score: 5.3/10. Published 2026-08-15.
How severe is CVE-2026-8840?
Medium severity. CVSS v3 base score is 5.3 out of 10.