CVE-2025-6681 is a stored Cross-Site Scripting (XSS) vulnerability affecting the Fan Page plugin for WordPress developed by delower186. This vulnerability exists in all versions up to and including 1.0.1 due to improper neutralization of input during web page generation, specifically involving the 'width' parameter. The root cause is insufficient input sanitization and output escaping, which allows an authenticated attacker with Contributor-level privileges or higher to inject arbitrary malicious scripts into pages. These scripts are stored persistently and execute whenever any user accesses the compromised page, potentially leading to session hijacking, privilege escalation, or other malicious activities. The vulnerability has a CVSS v3.1 base score of 6.4, indicating a medium severity level. The attack vector is network-based with low attack complexity and requires privileges equivalent to a Contributor role, but no user interaction is needed for exploitation. The scope is changed, meaning the vulnerability can affect resources beyond the vulnerable component, and the impact affects confidentiality and integrity but not availability. No known exploits are currently reported in the wild, and no official patches have been released yet. The vulnerability was publicly disclosed on July 29, 2025.

For European organizations using WordPress sites with the Fan Page plugin, this vulnerability poses a significant risk to the confidentiality and integrity of their web applications and user data. Since the exploit requires Contributor-level access, attackers who have compromised or gained such access (e.g., through phishing or weak credentials) can inject malicious scripts that execute in the context of other users, including administrators and visitors. This can lead to theft of session cookies, unauthorized actions performed on behalf of users, defacement, or distribution of malware. Given the widespread use of WordPress in Europe for corporate, governmental, and small business websites, exploitation could result in reputational damage, regulatory non-compliance (e.g., GDPR breaches due to data exposure), and financial losses. The persistent nature of stored XSS increases the risk as multiple users can be affected over time. Although no availability impact is noted, the integrity and confidentiality breaches are critical concerns, especially for sectors handling sensitive information such as finance, healthcare, and public administration.

European organizations should immediately audit their WordPress installations to identify the presence of the Fan Page plugin by delower186. Until an official patch is released, the following specific mitigations are recommended: 1) Restrict Contributor-level access strictly to trusted users and review existing user roles and permissions to minimize the attack surface. 2) Implement Web Application Firewall (WAF) rules to detect and block suspicious payloads targeting the 'width' parameter in HTTP requests related to the Fan Page plugin. 3) Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts on affected pages. 4) Conduct thorough input validation and output encoding on all user-supplied data at the application level if customization is possible. 5) Monitor logs for unusual activities related to page edits or script injections. 6) Consider temporarily disabling or removing the Fan Page plugin if it is not critical to operations until a secure version is available. 7) Educate users with Contributor or higher privileges about phishing and credential security to prevent privilege escalation. These targeted measures go beyond generic advice by focusing on access control, detection, and containment specific to this vulnerability's exploitation vector.