CVE-2025-11874 identifies a stored Cross-Site Scripting (XSS) vulnerability in the Slippy Slider – Responsive Touch Navigation Slider plugin for WordPress, versions up to and including 2.0. The vulnerability arises from improper neutralization of script-related HTML tags (CWE-80) within the plugin's 'slippy-slider' shortcode. Specifically, the plugin fails to adequately sanitize and escape user-supplied attributes, allowing authenticated users with contributor-level access or higher to inject arbitrary JavaScript code into pages. This malicious code is stored persistently and executed in the browsers of any users who visit the compromised pages, potentially enabling session hijacking, privilege escalation, defacement, or redirection to malicious sites. The attack vector requires authentication with contributor privileges and user interaction (visiting the infected page). The CVSS 3.1 score is 5.4, reflecting medium severity, with an attack vector of network, low attack complexity, privileges required, user interaction required, and scope changed due to impact beyond the attacker’s privileges. No public exploits have been reported yet, and no official patches are currently available, though updates should be expected. The vulnerability highlights the risks of insufficient input validation and output encoding in WordPress plugins, especially those that accept user-generated content or attributes.

For European organizations, this vulnerability poses a moderate risk primarily to websites using WordPress with the Slippy Slider plugin installed. Since the exploit requires contributor-level access, the threat is significant in environments where multiple users can add or edit content, such as corporate blogs, news portals, and e-commerce sites. Successful exploitation could lead to theft of session cookies, enabling attackers to impersonate users with higher privileges, potentially leading to data breaches or unauthorized administrative actions. It could also facilitate defacement or distribution of malware to site visitors, damaging organizational reputation and customer trust. The impact on confidentiality and integrity is moderate due to the ability to execute arbitrary scripts, while availability impact is minimal. Given the widespread use of WordPress across Europe, especially in countries with large digital economies, this vulnerability could affect a broad range of sectors including media, retail, and government services.

Organizations should immediately audit user roles and restrict contributor-level access to trusted personnel only. Implement strict content review processes to detect and prevent malicious shortcode usage. Employ Web Application Firewalls (WAFs) with rules to detect and block suspicious script injections in shortcode attributes. Monitor website logs for unusual activity related to the 'slippy-slider' shortcode. Until an official patch is released, consider disabling or removing the Slippy Slider plugin if feasible. Encourage plugin developers to release updates with proper input sanitization and output escaping. Additionally, educate content contributors about safe content practices and the risks of injecting untrusted code. Regularly update WordPress core and all plugins to minimize exposure to known vulnerabilities.