CVE-2026-93875 in JetAppointment Plugin
Summary
by MITRE • 10/02/2026
The JetAppointment plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'friendlyTime' parameter in all versions up to, and including, 2.5.2.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The injected payload is stored in the wp_jet_appointments_meta table via the unauthenticated jet_engine_form_booking_submit endpoint and executes in the administrator's browser when the appointment details popup is opened in the WordPress admin panel.
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Analysis
by VulDB Data Team • 10/02/2026
The JetAppointment plugin for WordPress, specifically versions up to 2.5.2.1, contains a critical security flaw classified as Stored Cross-Site Scripting (XSS). This vulnerability stems from insufficient input sanitization and output escaping mechanisms within the application code. The specific point of failure is the friendlyTime parameter, which accepts user-supplied data without adequate validation or encoding before storage. Because this processing occurs on the server side prior to database insertion, the malicious payload becomes persistent rather than transient, distinguishing it from reflected XSS attacks where the script executes immediately in the context of a single request.
The exploitation vector for this vulnerability is notably severe due to its unauthenticated nature. Attackers do not need valid credentials or any form of authentication to trigger the injection. The data flow begins when an attacker submits a crafted HTTP request containing malicious JavaScript code within the friendlyTime parameter to the jet_engine_form_booking_submit endpoint. This endpoint processes the submission and stores the unsanitized input directly into the wp_jet_appointments_meta database table. Consequently, every subsequent retrieval of this appointment data will include the injected script, effectively turning legitimate administrative pages into vectors for attack without further interaction from the attacker at that stage.
The operational impact is significant because the payload executes in the context of an administrator's browser session. When a WordPress administrator opens the appointment details popup within the admin panel to review booking information, the stored malicious script is rendered and executed by the browser. This execution occurs with the privileges of the logged-in user, who typically holds administrative rights over the entire website infrastructure. As such, successful exploitation allows an unauthenticated attacker to achieve arbitrary code execution on behalf of the administrator. The consequences can include complete compromise of the WordPress installation, theft of session cookies leading to account takeover, defacement of the site, or redirection of users to malicious phishing sites designed to harvest credentials from other visitors.
From a classification perspective, this vulnerability aligns with CWE-79, which describes Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting. Specifically, it represents Stored XSS where the payload is saved on the target server and served later to victims. In terms of adversary tactics, this attack maps to MITRE ATT&CK technique T1059, Command and Scripting Interpreter, specifically through JavaScript execution in a browser context. It also relates to TA0003 Persistence if the attacker uses the compromised session to create new admin accounts or modify site settings to maintain access, and TA0005 Defense Evasion if they attempt to hide their presence by modifying logs or other administrative records via the injected script.
Mitigation strategies must address both immediate remediation and long-term security hygiene. The primary defense is upgrading the JetAppointment plugin to a version newer than 2.5.2.1, where developers have presumably implemented proper input validation and output encoding for the friendlyTime parameter and related fields. Until an update can be applied, administrators should consider disabling or removing the plugin if it is not essential to their operations. Additionally, implementing a Web Application Firewall (WAF) with rules capable of detecting and blocking XSS payloads in POST requests targeting booking endpoints can provide a layer of defense against exploitation attempts. Regular security audits focusing on input sanitization practices across all user-facing forms are also recommended to prevent similar vulnerabilities from being introduced into the codebase in future updates or custom integrations.