Booking calendar, Appointment Booking System <= 3.2.36 - Unauthenticated Insecure Direct Object Reference
Strategic Overview
- Status
- Unpatched
- Affected Plugin
- Booking calendar, Appointment Booking System
- Affected Version
<= 3.2.36- CVSS
- 5.3Medium
- Weakness type
- CWE-639 · Authorization Bypass Through User-Controlled Key
- CVE
CVE-2026-73395
At a glance
CVE-2026-73395 is a medium-severity Authorization Bypass Through User-Controlled Key vulnerability in the Booking calendar, Appointment Booking System WordPress plugin, affecting versions <= 3.2.36. It carries a CVSS score of 5.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. No fixed release has been reported yet; treat installations running this software as exposed. Disclosed August 2026, reported by Jakub Herman.
Vulnerability Overview
The Booking calendar, Appointment Booking System plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 3.2.36. This is due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to perform an unauthorized action.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user.
CWE-639: Authorization Bypass Through User-Controlled Key
Reaching this weakness in Booking calendar, Appointment Booking System <= 3.2.36 takes no account at all. Authorization bypass through a user-controlled key, often called insecure direct object reference, means the application looks up a record by an identifier from the request without checking that the caller owns it.
Changing a number in the request is enough to read or modify other users' records, which on commerce and membership sites means customer data. No fixed build of this plugin is recorded for Booking calendar, Appointment Booking System yet, so installs running <= 3.2.36 stay exposed until the vendor ships one.
Remediation
No known patch available. Please review the vulnerability's details in depth and employ mitigations based on your organization's risk tolerance. It may be best to uninstall the affected software and find a replacement.
How does WordSec protect against this?
This one needs no account at all, which puts it outside what login hardening can reach; WordSec's login security narrows the account-level paths around it, and the firewall is what inspects the request itself. No patched version is recorded yet, which is the case where a filtering layer matters most, because there is nothing to update to.
- Login Security
- Alerts
External References
Related records
Other vulnerabilities in Booking calendar, Appointment Booking System
- 9.8CVE-2022-3982: Booking calendar Arbitrary File Upload
CVE-2022-3982 - 8.8CVE-2018-5673: Booking calendar, Appointment Booking System CSRF
CVE-2018-5673 - 7.5CVE-2018-10363: Booking calendar Parameter Manipulation
CVE-2018-10363 - 7.2CVE-2026-14334: Booking calendar Stored XSS
CVE-2026-14334 - 7.2CVE-2026-25435: Booking calendar Stored XSS
CVE-2026-25435 - 7.2CVE-2024-9504: Booking calendar, Appointment Booking System Stored XSS
CVE-2024-9504 - 7.2Booking Calendar WpDevArt <= 3.2.11 SQL Injection
- 7.2Booking calendar Multiple Authenticated(Editor+) SQL Injection
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