CVE-2026-14224 in Easy Appointments Plugin
Summary
by MITRE • 07/29/2026
The Easy Appointments WordPress plugin through 3.12.26 does not verify that the appointment targeted by its customer-data update action belongs to the current user; the action only checks a shared nonce that any authenticated user can obtain from their own appointment's edit form. A subscriber-level user with an appointment of their own can therefore reuse that nonce to overwrite the customer metadata (email, name, phone, description) of another user's appointment. Because the Easy Appointments WordPress plugin through 3.12.26 then treats that metadata as the appointment's contact data, a subsequent administrator status change with customer notifications enabled delivers the victim's appointment notification to the attacker-controlled email address.
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Analysis
by VulDB Data Team • 07/29/2026
The vulnerability in the Easy Appointments WordPress plugin affects versions through 3.12.26 and represents a critical authorization flaw that allows authenticated users to manipulate appointment data belonging to other users. This issue stems from insufficient validation of user ownership during customer data update operations, creating a privilege escalation scenario where lower-privileged users can access and modify higher-value targets within the system. The vulnerability operates through a nonce reuse mechanism that should have been scoped to individual user appointments but instead provides universal access to appointment modification functions for any authenticated user who can obtain a valid nonce from their own appointment edit form.
The technical implementation flaw manifests in the plugin's failure to perform proper user ownership verification before executing customer metadata updates. When users access their appointment edit forms, the system generates a shared nonce value that should be unique to each user's specific appointment but is instead being reused across different appointments within the same user context. This design oversight creates a path where a subscriber-level attacker can extract a valid nonce from their own appointment and then apply it to modify another user's appointment data through the customer-data update action. The vulnerability specifically targets the metadata fields including email, name, phone number, and description that are stored as part of appointment contact information.
The operational impact of this vulnerability extends beyond simple data manipulation to enable more sophisticated attacks involving notification hijacking and social engineering. When an administrator changes an appointment status with customer notifications enabled, the system retrieves the appointment's contact metadata to determine the notification recipient address. Since the attacker has successfully overwritten another user's email address through the nonce reuse attack, they receive all subsequent notifications intended for the legitimate appointment owner. This creates a persistent backdoor for information leakage and potential further exploitation where attackers can monitor communications, gather intelligence about victims, or use compromised contact information for phishing campaigns.
The vulnerability aligns with CWE-863, which addresses "Incorrect Authorization" in software systems, specifically targeting scenarios where access control checks fail to properly validate user permissions. The attack pattern follows the characteristics described in MITRE ATT&CK technique T1078.004 for valid accounts and T1566 for social engineering through compromised credentials. From a security perspective, this represents a classic case of insufficient input validation combined with improper access control enforcement, where the system assumes that any authenticated user with a valid nonce can modify any appointment data within the system.
Mitigation strategies should focus on implementing proper user ownership verification before allowing appointment modifications, ensuring that nonces are scoped to specific user appointments rather than being shared across multiple appointment records. The plugin should enforce strict access control checks that validate not only the presence of a valid nonce but also confirm that the requesting user has legitimate authorization to modify the target appointment. Additionally, administrators should implement role-based access controls that limit appointment modification capabilities to users with appropriate privileges such as administrators or managers, and consider implementing audit logging for all appointment data modifications to detect unauthorized activities. The system should also validate that contact metadata changes are properly authenticated and cannot be manipulated through nonce reuse attacks.
The vulnerability highlights the importance of proper session management and authorization enforcement in WordPress plugins, particularly those handling sensitive user data and appointment scheduling systems. Organizations using this plugin should immediately update to versions that address the authorization flaw and conduct thorough security reviews of all plugin components that handle user data modifications. Regular security auditing of third-party WordPress plugins remains essential for maintaining system integrity, as this vulnerability demonstrates how seemingly minor implementation oversights can create significant security risks in collaborative environments where multiple user roles interact with shared data systems.