CVE-2026-91025 in Booking Manager Plugin
Summary
by MITRE • 09/23/2026
The Booking Manager WordPress plugin before 2.1.21 does not verify that a request to modify a user's Booking Manager WordPress plugin before 2.1.21-specific settings targets the requesting user's own account, allowing any authenticated user with subscriber-level access and above to create or overwrite the Booking Manager WordPress plugin before 2.1.21's per-user settings on arbitrary users, including administrators.
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Analysis
by VulDB Data Team • 09/23/2026
The vulnerability identified in versions of the Booking Manager WordPress plugin prior to release 2.1.21 constitutes a critical Broken Access Control flaw that undermines the fundamental security model of user-specific data isolation within the application environment. This issue stems from a failure in server-side validation logic, specifically regarding the verification of ownership for configuration settings associated with individual users. In secure web applications, when an authenticated entity requests to modify specific attributes or configurations tied to their identity, the backend system must rigorously validate that the target identifier matches the session credentials of the requester. The absence of this check in the Booking Manager plugin allows a malicious actor to manipulate the request parameters to specify arbitrary user identifiers rather than their own unique account ID. This design oversight effectively bypasses standard authorization checks, granting any authenticated user with subscriber-level access or higher privileges the ability to alter settings intended exclusively for other users within the system hierarchy.
From a technical perspective, this vulnerability is classified under CWE-284 Improper Access Control and aligns with MITRE ATT&CK technique T1078 Valid Accounts, as it leverages legitimate credentials to perform unauthorized actions. The core mechanism involves an insecure direct object reference pattern where the application trusts client-supplied input for user identification without cross-referencing it against the authenticated session's principal identity. By exploiting this flaw, an attacker can send crafted HTTP requests that target the administrative settings of high-privilege accounts, such as administrators or editors. This capability allows the creation or overwriting of per-user configuration data on arbitrary targets, effectively allowing lower-privileged users to inject malicious configurations into higher-privileged contexts. The lack of object-level permission checks means that the application treats any valid user session as authorized to modify resources belonging to other entities, violating the principle of least privilege and compromising the integrity of role-based access control mechanisms inherent in WordPress installations.
The operational impact of this vulnerability is severe due to its potential for privilege escalation and data manipulation across the entire platform. Since an attacker can overwrite settings on administrator accounts, they may be able to alter critical system behaviors, disable security features specific to those users, or inject malicious code snippets that execute with elevated privileges depending on how the Booking Manager plugin processes these configuration values. This could lead to a complete compromise of the WordPress installation if the overwritten settings influence output generation, database queries, or file inclusion mechanisms within the plugin's subsequent operations. Furthermore, this flaw facilitates lateral movement among user accounts, allowing an attacker who has gained initial access through a low-level subscriber account to escalate their influence by compromising administrative configurations. This undermines trust in multi-user environments where distinct roles are expected to maintain separate operational boundaries and data privacy.
Mitigation strategies must prioritize immediate patching of the Booking Manager plugin to version 2.1.21 or later, which addresses this access control deficiency by implementing strict validation checks that ensure modification requests only affect the requesting user's own profile settings. In addition to updating software, administrators should enforce strong password policies and multi-factor authentication for all accounts with subscriber-level access or higher to reduce the risk of initial credential compromise. Regular security audits focusing on input validation and authorization logic are recommended to detect similar patterns in custom themes or other plugins that may exhibit insecure direct object references. Monitoring server logs for unusual modification requests targeting administrative user IDs can also aid in early detection of exploitation attempts, ensuring rapid response before significant damage occurs within the WordPress ecosystem.