CVE-2025-4567 is a medium-severity Stored Cross-Site Scripting (XSS) vulnerability affecting the WordPress plugin 'Post Slider and Post Carousel with Post Vertical Scrolling Widget' in versions prior to 3.2.10. The vulnerability arises because the plugin fails to properly validate and escape certain widget options before rendering them on pages or posts where the widget block is embedded. This improper sanitization allows users with the contributor role or higher to inject malicious JavaScript code that is stored persistently and executed in the context of other users viewing the affected pages. The vulnerability is classified under CWE-79, indicating a classic XSS flaw. The CVSS 3.1 base score is 4.8 (medium), with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), high privileges required (PR:H), user interaction required (UI:R), scope changed (S:C), and low impact on confidentiality and integrity (C:L, I:L), with no impact on availability (A:N). Although no known exploits are reported in the wild yet, the vulnerability poses a risk because contributor-level users are common in WordPress environments, and stored XSS can lead to session hijacking, privilege escalation, or distribution of malware through the affected site. The vulnerability affects all versions before 3.2.10, and no official patch links are currently provided, indicating that mitigation may require plugin updates once available or manual code fixes. The vulnerability was published on June 3, 2025, and assigned by WPScan.

For European organizations using WordPress sites with this plugin, the vulnerability could lead to unauthorized script execution in the browsers of site visitors or administrators. This can compromise user sessions, steal sensitive information, or facilitate further attacks such as phishing or malware distribution. Since contributor-level users can exploit this, insider threats or compromised contributor accounts pose a significant risk. The impact on confidentiality and integrity is low to moderate, but the scope can be broad if the site has many visitors or administrators. For organizations handling personal data under GDPR, such XSS vulnerabilities could lead to data breaches or non-compliance issues. Additionally, defacement or injection of malicious content could damage brand reputation and trust. The lack of availability impact means the site remains operational, but the security risk persists until remediated.

European organizations should immediately audit their WordPress installations to identify if the 'Post Slider and Post Carousel with Post Vertical Scrolling Widget' plugin is installed and its version. If the plugin is present and below version 3.2.10, they should prioritize updating it as soon as an official patch is released. In the interim, restrict contributor-level user permissions to trusted individuals only and monitor for suspicious activity. Implement Web Application Firewall (WAF) rules to detect and block typical XSS payloads targeting this plugin's widget parameters. Consider disabling or removing the plugin if it is not essential. Additionally, apply Content Security Policy (CSP) headers to limit the impact of injected scripts. Regularly scan WordPress sites with security tools that can detect stored XSS vulnerabilities. Educate content contributors about safe input practices and the risks of injecting untrusted content. Finally, monitor logs and user reports for signs of exploitation attempts.