CVE-2025-7809 is a Stored Cross-Site Scripting (XSS) vulnerability affecting the StreamWeasels Twitch Integration plugin for WordPress, specifically in all versions up to and including 1.9.3. The vulnerability arises from improper neutralization of user-supplied input in the 'data-uuid' attribute, where insufficient input sanitization and output escaping allow authenticated users with contributor-level access or higher to inject arbitrary JavaScript code. This malicious script is then stored and executed whenever any user accesses the affected page, potentially compromising user sessions, stealing cookies, or performing actions on behalf of users without their consent. The vulnerability has a CVSS 3.1 base score of 6.4, indicating a medium severity level. The attack vector is network-based with low attack complexity, requiring privileges equivalent to contributor-level access but no user interaction is needed for exploitation. The scope is changed, meaning the vulnerability affects components beyond the initially vulnerable plugin, potentially impacting the broader WordPress site. No known exploits are currently in the wild, and no patches have been officially released at the time of publication. The vulnerability is classified under CWE-79, which covers improper neutralization of input during web page generation leading to XSS. This vulnerability is significant because WordPress is widely used, and plugins like StreamWeasels Twitch Integration are popular for embedding Twitch streams, making it a valuable target for attackers aiming to compromise websites or their visitors through persistent script injection.

For European organizations, the impact of this vulnerability can be substantial, especially for those relying on WordPress sites with the StreamWeasels Twitch Integration plugin installed. Successful exploitation could lead to session hijacking, defacement, unauthorized actions performed on behalf of users, and potential data leakage. This is particularly critical for organizations handling sensitive user data or providing services through their websites. The persistent nature of stored XSS means that all visitors to the compromised pages are at risk, increasing the attack surface. Additionally, compromised websites can be used to distribute malware or conduct phishing campaigns targeting European users, undermining trust and potentially violating GDPR requirements related to data protection and breach notification. The requirement for contributor-level access means insider threats or compromised accounts could be leveraged to exploit this vulnerability, emphasizing the need for strict access controls. Although no known exploits are currently active, the medium severity and ease of exploitation suggest that attackers may develop exploits, increasing risk over time.

European organizations should immediately audit their WordPress installations to identify the presence of the StreamWeasels Twitch Integration plugin and verify the version in use. Until an official patch is released, organizations should consider disabling or uninstalling the plugin to eliminate the attack vector. Implementing strict role-based access control to limit contributor-level privileges can reduce the risk of exploitation. Web Application Firewalls (WAFs) with custom rules to detect and block suspicious payloads targeting the 'data-uuid' attribute can provide temporary protection. Security teams should monitor logs for unusual activity indicative of XSS attempts or unauthorized script injections. Additionally, applying Content Security Policy (CSP) headers can help mitigate the impact of injected scripts by restricting script execution sources. Regularly updating WordPress core, plugins, and themes is essential once patches become available. Finally, educating content contributors about safe input practices and monitoring user-generated content can help prevent exploitation.