CVE-2025-53559 is a high-severity reflected Cross-Site Scripting (XSS) vulnerability identified in the LambertGroup Universal Video Player addon for WPBakery Page Builder, affecting versions up to 3.2.1. This vulnerability arises from improper neutralization of user-supplied input during web page generation, classified under CWE-79. Specifically, the addon fails to adequately sanitize or encode input parameters that are reflected in the web page output, allowing an attacker to inject malicious scripts. When a victim visits a crafted URL containing malicious payloads, the injected script executes in the context of the victim's browser, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the user. The CVSS v3.1 base score of 7.1 reflects a network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), but requiring user interaction (UI:R). The scope is changed (S:C), indicating that the vulnerability can affect resources beyond the vulnerable component, and it impacts confidentiality, integrity, and availability to a limited extent (C:L/I:L/A:L). No known exploits are currently reported in the wild, and no patches have been published at the time of this report. The vulnerability affects a widely used WordPress page builder addon, which is commonly deployed on websites that embed video content, making it a relevant threat to web applications relying on this plugin for multimedia functionality.

For European organizations, this vulnerability poses a significant risk, especially for businesses and institutions that use WordPress sites with the Universal Video Player addon to deliver video content. Exploitation could lead to unauthorized access to user sessions, theft of sensitive information such as login credentials or personal data, and potential defacement or manipulation of website content. This could damage brand reputation, lead to regulatory non-compliance under GDPR due to data breaches, and disrupt service availability. Given the scope change in the CVSS vector, the attack could affect other components or user data beyond the immediate plugin context. Organizations in sectors such as e-commerce, media, education, and government that rely on WordPress for public-facing websites are particularly at risk. The requirement for user interaction means phishing or social engineering could be used to lure victims to malicious URLs, increasing the attack surface. The absence of known exploits currently provides a window for proactive mitigation, but the widespread use of WPBakery and its addons in Europe means the potential impact is broad.

European organizations should immediately audit their WordPress installations to identify the presence of the Universal Video Player addon for WPBakery Page Builder, specifically versions up to 3.2.1. Until an official patch is released, organizations should consider the following specific mitigations: 1) Implement Web Application Firewall (WAF) rules to detect and block reflected XSS payloads targeting the vulnerable parameters of the addon. 2) Employ Content Security Policy (CSP) headers to restrict the execution of inline scripts and untrusted sources, mitigating the impact of injected scripts. 3) Sanitize and validate all user inputs at the application level, especially those reflected in URLs or page content, using strict whitelisting approaches. 4) Educate users and administrators about the risks of clicking on suspicious links and encourage the use of browser security features that can block XSS attacks. 5) Monitor web server and application logs for unusual request patterns indicative of attempted exploitation. 6) If feasible, temporarily disable or replace the vulnerable addon with alternative video player solutions that do not exhibit this vulnerability. 7) Stay alert for vendor advisories and apply patches promptly once available. These targeted actions go beyond generic advice by focusing on the specific plugin and attack vector involved.