CVE-2026-123131 in GemBooking Plugin
Summary
by MITRE • 11/09/2026
The GemBooking WordPress plugin before 1.7.1 does not properly verify that a REST request is addressed to its own routes before temporarily granting staff users administrative capabilities, allowing users with the GemBooking WordPress plugin before 1.7.1's Staff role to delete arbitrary posts and update the site's settings.
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Analysis
by VulDB Data Team • 11/09/2026
The vulnerability identified in GemBooking versions prior to 1.7.1 represents a critical flaw in access control logic within the WordPress REST API implementation. The core issue stems from an insufficient verification mechanism when handling incoming HTTP requests. Specifically, the plugin fails to rigorously validate that a request is intended for its own designated endpoints before executing privilege escalation routines. This oversight allows attackers with lower-level privileges to exploit the misconfiguration by crafting malicious requests that bypass standard authorization checks, effectively tricking the application into treating unauthorized actions as legitimate administrative operations.
From a technical perspective, this flaw enables users assigned the Staff role within the GemBooking plugin to perform actions far beyond their intended scope of authority. The vulnerability allows these users to delete arbitrary posts across the WordPress installation and modify site-wide settings. This occurs because the code temporarily grants administrative capabilities without confirming that the request originates from an authorized context or is directed at a route specifically managed by the plugin itself. Consequently, any user with access to the Staff role can manipulate core website data and configuration parameters, leading to potential defacement, data loss, or complete compromise of the underlying WordPress environment.
The operational impact of this vulnerability is severe, as it undermines the fundamental principle of least privilege in web application security. By allowing staff users to delete arbitrary posts, an attacker could remove critical content, disrupt business operations, or cause denial of service conditions for legitimate visitors. Furthermore, the ability to update site settings opens the door to persistent backdoors, such as changing admin credentials, altering theme files, or modifying database configurations. This level of access effectively grants full control over the WordPress instance, enabling further exploitation vectors like remote code execution through uploaded malicious plugins or themes if those settings allow it.
This vulnerability aligns with CWE-269, which describes Improper Privilege Control, as well as CWE-862, Missing Authorization, since the application fails to enforce proper access controls on protected resources. In terms of attack patterns, this behavior is consistent with MITRE ATT&CK techniques related to privilege escalation and unauthorized resource modification. The lack of strict route validation also touches upon aspects of CWE-915, Improper Control of Dynamically-Identified Variables, where the application incorrectly handles dynamic input without adequate sanitization or verification.
To mitigate this risk, administrators must immediately update the GemBooking plugin to version 1.7.1 or later, which addresses these access control deficiencies by implementing robust validation for REST API requests. Until an upgrade is possible, it is advisable to restrict user roles and limit the capabilities assigned to staff members as much as possible. Additionally, deploying a Web Application Firewall can help detect and block anomalous request patterns that attempt to exploit this privilege escalation flaw. Regular security audits and code reviews focusing on authorization logic in custom plugins are essential preventive measures against similar vulnerabilities in WordPress ecosystems.