CVE-2025-4406 is a stored Cross-Site Scripting (XSS) vulnerability affecting the wpForo Forum plugin for WordPress, developed by tomdever. This vulnerability exists in all versions up to and including 2.4.5. The root cause is insufficient input sanitization and output escaping of SVG file uploads, which allows authenticated users with Subscriber-level access or higher to inject arbitrary JavaScript code into SVG files. When other users access pages containing these malicious SVG files, the injected scripts execute in their browsers. This vulnerability leverages the fact that SVG files can contain embedded scripts, and if these files are not properly sanitized, they become a vector for persistent XSS attacks. The CVSS v3.1 base score is 5.4 (medium severity), with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), requiring privileges (PR:L), user interaction (UI:R), and scope changed (S:C). The impact affects confidentiality and integrity but not availability. Exploitation requires an authenticated user with at least Subscriber privileges to upload a crafted SVG file, which then executes scripts in the context of other users visiting the forum pages. No known exploits are currently in the wild, and no official patches have been linked yet. This vulnerability is significant because wpForo is a popular forum plugin for WordPress, widely used to add community features to websites. Stored XSS can lead to session hijacking, defacement, phishing, or distribution of malware, impacting user trust and site integrity.

For European organizations using WordPress with the wpForo Forum plugin, this vulnerability poses a risk of persistent XSS attacks that can compromise user accounts, steal session cookies, or perform actions on behalf of users. This can lead to data breaches involving personal data protected under GDPR, reputational damage, and potential regulatory penalties. Since the attack requires authenticated access, insider threats or compromised accounts can be leveraged to exploit this vulnerability. The scope change means that the vulnerability can affect users beyond the initial attacker, increasing the risk of widespread impact on community forums or customer engagement platforms. Organizations relying on wpForo for customer support, community interaction, or internal collaboration may face disruptions and loss of user trust. Additionally, attackers could use this vector to deliver malware or conduct phishing campaigns targeting European users, further increasing the threat landscape.

1. Immediately restrict SVG file uploads or disable SVG support in wpForo until a patch is available. 2. Implement strict input validation and sanitization on SVG uploads, removing any embedded scripts or potentially dangerous elements before storage or display. 3. Apply output encoding/escaping when rendering SVG files in web pages to prevent script execution. 4. Enforce the principle of least privilege by reviewing user roles and permissions, limiting Subscriber-level users' ability to upload files if possible. 5. Monitor forum activity and uploaded files for suspicious SVG content or unusual behavior. 6. Educate users and administrators about the risks of XSS and encourage reporting of anomalies. 7. Keep WordPress core and all plugins, including wpForo, updated to the latest versions once a security patch is released. 8. Consider deploying Web Application Firewalls (WAFs) with rules to detect and block malicious SVG payloads. 9. Conduct regular security audits and penetration testing focusing on file upload functionalities.