CVE-2026-123064 in WP BASE Booking of Appointments, Services and Events Plugin
Summary
by MITRE • 11/09/2026
The WP BASE Booking of Appointments, Services and Events WordPress plugin before 6.5.1 does not properly restrict access to one of its user-creation actions, allowing authenticated users with Subscriber-level access and above to create a new administrator account and thereby escalate their privileges.
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Analysis
by VulDB Data Team • 11/09/2026
The vulnerability identified in the WP BASE Booking of Appointments, Services and Events WordPress plugin prior to version 6.5.1 represents a critical failure in server-side access control mechanisms. This flaw specifically affects user creation endpoints within the plugin's administrative interface. The core technical issue stems from an insufficient check on the privileges required to invoke specific functions responsible for adding new users to the system. In a properly secured application, actions that modify high-privilege roles or create accounts with elevated permissions must be strictly gated behind robust authorization checks that verify not only authentication but also sufficient administrative rights. However, in this instance, the plugin fails to validate whether the initiating user possesses the necessary capabilities before processing the request to create a new account. This oversight allows any authenticated user who has logged into the WordPress site and holds at least Subscriber-level access or higher to bypass intended restrictions and execute privileged operations that should be reserved exclusively for administrators.
From an operational perspective, this vulnerability enables unauthorized privilege escalation, which is one of the most severe categories of security risks in web applications. An attacker with low-privileged access can exploit this flaw to create a new user account assigned the Administrator role. Once created, this malicious administrator account provides full control over the WordPress installation. This includes the ability to install and activate plugins, modify themes, edit core files, execute database queries, and potentially upload executable scripts or web shells if file upload restrictions are not strictly enforced elsewhere in the system. The impact extends beyond simple administrative access; it compromises the integrity of the entire content management platform. Attackers can use this elevated access to deface websites, steal sensitive data stored within the WordPress database such as user credentials and personal information, inject malicious code into posts or pages for cross-site scripting attacks against visitors, or install backdoors that persist even if the initial vulnerability is patched.
This type of flaw aligns directly with CWE-269, which describes Improper Privilege Control, where a software application does not properly assign privileges to an actor based on their role and responsibilities. Furthermore, in the context of the MITRE ATT&CK framework for enterprise security, this behavior corresponds to techniques related to Account Manipulation, specifically T1136, which involves creating accounts to maintain access or escalate privileges. The exploitation path typically falls under Initial Access via Valid Accounts if the attacker already has legitimate credentials due to weak password policies or credential stuffing attacks, followed by Privilege Escalation through improper authorization checks. This scenario highlights a common weakness in many WordPress plugins where developers assume that because a user is logged in, they should have access to all administrative features provided by the plugin, failing to implement granular capability checks specific to each action.
Mitigation for this vulnerability requires immediate remediation at both the application and infrastructure levels. The primary and most effective solution is to upgrade the WP BASE Booking of Appointments, Services and Events plugin to version 6.5.1 or later, where the developers have implemented proper authorization logic to restrict user creation actions to users with explicit Administrator capabilities. In environments where immediate patching is not feasible due to compatibility concerns, temporary mitigations should be employed. These include restricting access to the WordPress admin area using IP whitelisting if possible, ensuring that all administrative accounts use strong, unique passwords and multi-factor authentication to reduce the risk of initial credential compromise, and regularly auditing user roles within the WordPress dashboard to detect any unauthorized administrator accounts promptly. Additionally, implementing a Web Application Firewall can help block common exploitation patterns associated with privilege escalation attempts by monitoring for anomalous requests targeting user creation endpoints from non-administrative sessions. Regular security audits and code reviews focusing on authorization checks are essential to prevent similar flaws in future updates or other plugins installed within the same environment.