Authorization Bypass Vulnerability in TrueBooker Appointment Booking Plugin for WordPress
CVE-2026-18315

9.8CRITICAL

Key Information:

Vendor

WordPress
Status
Truebooker – Appointment Booking And Scheduler System
Vendor
CVE Published:
19 August 2026

What is CVE-2026-18315?

The TrueBooker Appointment Booking and Scheduler System plugin for WordPress contains a vulnerability that allows unauthorized users to bypass authentication controls. This occurs due to the lack of checks in the admin_user_create_cus AJAX handler, which accepts an attacker-controlled truebooker_wp_user_id parameter without proper validation. As a result, an attacker can modify the email address of any WordPress user, potentially including administrators. This vulnerability could lead to a complete account takeover through the standard WordPress lost-password process.

Affected Version(s)

TrueBooker – Appointment Booking and Scheduler System 0 <= 1.2.6

References

https://www.wordfence.com/threat-intel/vulnerabilities/id...
https://plugins.svn.wordpress.org/truebooker-appointment-...
https://plugins.svn.wordpress.org/truebooker-appointment-...

CVSS V3.1

Score:
9.8
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Décio Brandão
.