CVE-2025-66057 is a DOM-based Cross-site Scripting (XSS) vulnerability identified in the Bold Page Builder plugin developed by boldthemes, affecting all versions up to and including 5.5.2. The vulnerability stems from improper neutralization of user-supplied input during the dynamic generation of web pages, allowing malicious scripts to be injected and executed within the victim's browser context. Unlike traditional reflected or stored XSS, DOM-based XSS occurs entirely on the client side, where the manipulation of the Document Object Model leads to script execution without server-side sanitization. This flaw can be exploited by attackers who craft malicious URLs or payloads that, when visited by users, execute arbitrary JavaScript code. The consequences include theft of session cookies, redirection to malicious sites, unauthorized actions performed on behalf of the user, and potential compromise of sensitive data. The vulnerability does not require authentication, increasing its risk profile, but does require user interaction to trigger the payload. Although no public exploits have been reported yet, the widespread use of Bold Page Builder in WordPress sites makes this a significant concern. The absence of an official patch or CVSS score at the time of publication necessitates proactive mitigation and monitoring by affected parties.

For European organizations, the impact of CVE-2025-66057 can be substantial, particularly for those relying on WordPress websites utilizing the Bold Page Builder plugin. Successful exploitation can lead to session hijacking, enabling attackers to impersonate legitimate users, including administrators, potentially leading to unauthorized data access or modification. This undermines the confidentiality and integrity of sensitive information and can damage organizational reputation. Additionally, attackers could use the vulnerability to deliver further malware or phishing campaigns targeting European users. The disruption to availability is generally limited but could occur if attackers deface websites or inject disruptive scripts. Given the high adoption of WordPress and related plugins in Europe, especially in sectors like e-commerce, media, and public services, the threat could affect a broad range of organizations. Furthermore, regulatory frameworks such as GDPR impose strict data protection requirements, and exploitation of this vulnerability could lead to compliance violations and financial penalties.

To mitigate CVE-2025-66057, European organizations should: 1) Monitor for and apply security updates from boldthemes promptly once patches are released, as no official patch is currently available. 2) Implement strict input validation and sanitization on all user inputs, especially those influencing page generation in the Bold Page Builder environment. 3) Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS attacks. 4) Conduct regular security audits and penetration testing focusing on client-side vulnerabilities in web applications using Bold Page Builder. 5) Educate users and administrators about the risks of clicking on suspicious links that could trigger DOM-based XSS payloads. 6) Utilize Web Application Firewalls (WAFs) with rules tailored to detect and block XSS attack patterns targeting the Bold Page Builder plugin. 7) Monitor web server and application logs for unusual activities indicative of exploitation attempts. 8) Consider temporary disabling or replacing the Bold Page Builder plugin with more secure alternatives if immediate patching is not feasible.