CVE-2026-57639 in WP Booking System Plugin
Summary
by MITRE • 11/04/2026
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Roland Murg WP Booking System wp-booking-system allows Reflected XSS.This issue affects WP Booking System: from n/a through 2.1.0.6.
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Analysis
by VulDB Data Team • 11/04/2026
The identified security flaw represents a classic instance of Improper Neutralization of Input During Web Page Generation, commonly known as Cross-Site Scripting or XSS. Specifically, this vulnerability manifests as a Reflected XSS within the Roland Murg WP Booking System plugin for WordPress, affecting versions ranging from no specific lower bound up through version 2.1.0.6. In a reflected cross-site scripting attack, malicious script code is embedded directly into HTTP requests and then immediately returned by the web application in an error message or search result page without proper sanitization. This means that the vulnerability does not persist on the server but relies entirely on social engineering to trick a victim into clicking a specially crafted link containing the malicious payload.
From a technical perspective, the root cause lies in the insufficient validation and encoding of user-supplied input before it is rendered back to the browser within an HTML context. When the application processes data submitted via query parameters or form fields related to booking operations, it fails to strip out potentially executable JavaScript code or escape special characters such as angle brackets and quotes. Consequently, when this tainted data is echoed back in the response body, the victim's web browser interprets the injected script as legitimate content belonging to the site. This allows an attacker to execute arbitrary client-side scripts within the security context of the trusted domain hosting the WordPress installation.
The operational impact of this vulnerability extends beyond simple defacement or alert boxes. An attacker can leverage reflected XSS to steal session cookies, which are often transmitted without sufficient HttpOnly flags in older configurations, thereby facilitating account takeover attacks against administrative users who manage bookings and customer data. Furthermore, the malicious script can perform actions on behalf of the authenticated user, such as modifying booking details, deleting reservations, or exfiltrating sensitive information stored within local storage variables if accessible via DOM manipulation techniques. This compromises the confidentiality and integrity of the application's data while undermining the trust users place in the booking platform.
In terms of industry standard classification, this vulnerability aligns with CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'). The specific behavior falls under the sub-category of Reflected XSS where input is not validated before being sent back to the user. Within the MITRE ATT&CK framework for enterprise security, this technique maps to T1059.007: JavaScript and potentially T1204.002: Malicious Link, as it requires the victim to interact with a maliciously crafted URL to trigger the execution of the payload. Understanding these mappings helps in categorizing the risk accurately within broader security posture assessments and threat modeling exercises.
To mitigate this vulnerability, immediate action is required by upgrading the Roland Murg WP Booking System plugin to version 2.1.0.7 or any later release where the developer has implemented proper input sanitization and output encoding mechanisms. Developers should ensure that all user inputs are validated against a whitelist of expected values before processing and that all dynamic content rendered in HTML contexts is properly encoded using functions such as htmlspecialchars with appropriate flags like ENT_QUOTES and UTF-8 character set specification. Additionally, implementing Content Security Policy headers can provide an additional layer of defense by restricting the sources from which scripts can be loaded or executed, thereby limiting the impact even if a reflection occurs. Regular security audits and static code analysis tools should also be employed to detect similar patterns in other parts of the application logic.