CVE-2025-58787 is a medium-severity stored Cross-Site Scripting (XSS) vulnerability affecting the Themify Popup plugin developed by themifyme, specifically versions up to 1.4.4. The vulnerability arises due to improper neutralization of input during web page generation, classified under CWE-79. Stored XSS occurs when malicious input is persistently stored by the application and later rendered in web pages without proper sanitization or encoding, allowing attackers to inject and execute arbitrary JavaScript code in the context of users' browsers. This vulnerability requires low privileges (PR:L) and user interaction (UI:R) to exploit, but it can lead to a complete compromise of confidentiality, integrity, and availability of affected web applications (scope changed). The CVSS vector indicates network attack vector (AV:N), low attack complexity (AC:L), and partial impacts on confidentiality, integrity, and availability (C:L/I:L/A:L). Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk to websites using the Themify Popup plugin, especially those that handle sensitive user data or perform critical functions. Exploitation could enable attackers to steal session cookies, perform actions on behalf of users, deface websites, or deliver malware payloads, thereby undermining user trust and organizational security posture.

For European organizations, the impact of this vulnerability can be substantial, particularly for businesses relying on WordPress sites with the Themify Popup plugin for marketing, customer engagement, or e-commerce. Exploitation could lead to unauthorized access to user accounts, data leakage, and reputational damage. Given the GDPR regulatory environment in Europe, any data breach resulting from such an XSS attack could trigger significant compliance penalties and legal consequences. Additionally, compromised websites could be used as vectors for further attacks against European users, amplifying the threat. Organizations in sectors such as finance, healthcare, and retail, which often use popup plugins for user interaction, are at higher risk. The vulnerability could also disrupt availability if attackers leverage it to inject malicious scripts that degrade site performance or cause denial of service. Overall, the threat undermines both user trust and operational continuity for affected European entities.

To mitigate this vulnerability, European organizations should immediately audit their WordPress installations to identify the presence of the Themify Popup plugin and verify its version. Although no official patch links are provided yet, organizations should monitor vendor advisories for updates or patches addressing CVE-2025-58787. In the interim, applying Web Application Firewall (WAF) rules to detect and block suspicious input patterns related to XSS can reduce risk. Implementing Content Security Policy (CSP) headers to restrict script execution sources will also help mitigate exploitation impact. Additionally, organizations should enforce strict input validation and output encoding practices on any custom code interacting with the plugin. Regular security scanning and penetration testing focused on XSS vulnerabilities are recommended to detect potential exploitation. Finally, educating site administrators and users about the risks of interacting with suspicious popups can reduce successful exploitation likelihood.