CVE-2025-12025 is a stored cross-site scripting (XSS) vulnerability classified under CWE-79, found in the mahabubs YouTube Subscribe plugin for WordPress. This vulnerability exists in all versions up to and including 3.0.0 due to insufficient input sanitization and output escaping in the plugin's administrative settings. Specifically, authenticated users with administrator-level permissions or higher can inject arbitrary JavaScript code into pages generated by the plugin. The vulnerability is limited to multi-site WordPress installations or those where the unfiltered_html capability is disabled, which restricts the ability to post unfiltered HTML content. When exploited, the injected scripts execute in the context of users accessing the affected pages, potentially allowing attackers to hijack sessions, deface content, or perform actions with the victim's privileges. The CVSS 3.1 score of 4.4 reflects a medium severity, with network attack vector, high attack complexity, requiring privileges and no user interaction. The scope is changed as the vulnerability affects multiple components within the WordPress multi-site environment. No patches or known exploits are currently available, increasing the importance of monitoring and applying updates once released. This vulnerability highlights the risks of improper input validation in WordPress plugins, especially in multi-site configurations where administrative control is shared across multiple sites.

For European organizations, the impact of CVE-2025-12025 can be significant in environments using WordPress multi-site installations with the mahabubs YouTube Subscribe plugin. Successful exploitation could allow attackers with admin privileges to inject malicious scripts, potentially leading to session hijacking, unauthorized actions, or defacement of administrative pages. Although the vulnerability requires high privileges, insider threats or compromised administrator accounts could leverage this flaw to escalate attacks. The confidentiality and integrity of administrative data could be compromised, affecting trust and operational security. Availability impact is minimal as the vulnerability does not directly cause denial of service. Given the widespread use of WordPress in Europe, especially among SMEs and public sector entities, this vulnerability could expose a broad attack surface if not mitigated. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits once patches are released or if the vulnerability is disclosed publicly.

European organizations should immediately audit their WordPress environments to identify installations using the mahabubs YouTube Subscribe plugin, particularly in multi-site configurations or where unfiltered_html is disabled. Until an official patch is released, administrators should restrict plugin usage to trusted personnel and consider disabling or removing the plugin if it is not essential. Implement strict access controls and monitor administrator accounts for suspicious activity to reduce the risk of insider exploitation. Employ Web Application Firewalls (WAFs) with custom rules to detect and block suspicious script injection attempts targeting the plugin's admin pages. Regularly update WordPress core and plugins to the latest versions once patches become available. Additionally, conduct security awareness training for administrators to recognize and prevent misuse of admin privileges. Logging and monitoring of administrative actions should be enhanced to detect potential exploitation attempts early. Finally, consider isolating multi-site installations or limiting plugin usage to single-site environments where feasible to reduce attack surface.