CVE-2026-8840
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk24th percentile - higher than 24% of all known CVEs
Summary
The Booking calendar, Appointment Booking System plugin for WordPress up to version 3.2.36 has an authorization bypass vulnerability. Unauthenticated attackers can mark reservations as paid or completed, cancel legitimate payments, auto-approve reservations, and trigger transactional emails.
Risk Assessment
The risk includes manipulation of reservations and payments, potentially leading to financial losses and data integrity issues. Auto-approval requires the 'enable_psuccess_approval' option, but payment status manipulation is always possible.
Recommendation
Update the plugin to a patched version immediately. Also, review logs for unauthorized reservation changes and consider additional security measures such as nonce verification.
Other vulnerabilities in Booking calendar, Appointment Booking System
See all- CVE-2026-73395Medium
The Booking calendar, Appointment Booking System plugin version 3.2.36 and earlier has an insecure direct object references (IDOR) vulnerability that does not require authentication. This means an unauthenticated attacker can access objects (e.g., bookings) without authorization.
- CVE-2026-57778Medium
The Booking calendar, Appointment Booking System plugin for WordPress has a missing authorization vulnerability, allowing exploitation of incorrectly configured access control security levels. This issue affects versions up to and including 3.2.36.
- CVE-2025-67574Medium
The Booking calendar, Appointment Booking System plugin (by wpdevart) contains a Missing Authorization vulnerability that allows exploiting incorrectly configured access control security levels. This issue affects Booking calendar, Appointment Booking System from n/a through <= 3.2.30.
Original NVD description (English source)
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 data from NVD (NIST) · CISA KEV · EPSS