CVE-2025-58654 is a DOM-Based Cross-Site Scripting (XSS) vulnerability classified under CWE-79, affecting the xili-language plugin developed by Michel - xiligroup dev. This vulnerability arises from improper neutralization of input during web page generation, allowing malicious scripts to be injected and executed within the context of a user's browser session. Specifically, the flaw exists in versions of xili-language up to 2.21.3, enabling attackers to manipulate client-side scripts by injecting crafted payloads that the application fails to sanitize properly. The vulnerability requires at least low privileges (PR:L) and user interaction (UI:R) to be exploited, but it can lead to a complete compromise of confidentiality, integrity, and availability within the affected scope (S:C), meaning the impact can extend beyond the vulnerable component to other parts of the system or user data. The CVSS v3.1 base score is 6.5, indicating a medium severity level. Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk if weaponized, particularly in environments where the xili-language plugin is used to manage multilingual content on websites. Attackers exploiting this vulnerability could execute arbitrary JavaScript in the victim's browser, potentially leading to session hijacking, credential theft, unauthorized actions on behalf of the user, or redirection to malicious sites.

For European organizations, the impact of this DOM-Based XSS vulnerability can be substantial, especially for those relying on the xili-language plugin to provide multilingual support on their websites. Successful exploitation could compromise user data confidentiality by stealing session cookies or personal information, undermine data integrity by manipulating displayed content or user inputs, and affect availability by triggering disruptive scripts. This is particularly critical for sectors such as e-commerce, government portals, and financial services where trust and data protection are paramount. Additionally, given the GDPR regulations in Europe, any breach involving personal data could lead to severe legal and financial repercussions. The vulnerability's ability to affect multiple users through client-side script execution increases the potential attack surface, making it a concern for organizations with a large and diverse user base across European countries.

To mitigate this vulnerability effectively, European organizations should prioritize updating the xili-language plugin to a patched version once available. In the absence of an official patch, organizations can implement strict Content Security Policies (CSP) to restrict the execution of unauthorized scripts and reduce the impact of injected code. Input validation and output encoding should be enforced rigorously on all user-controllable inputs, especially those influencing client-side scripts or DOM elements. Developers should audit the plugin's source code to identify and sanitize all dynamic content generation points. Additionally, employing security headers such as X-XSS-Protection and ensuring secure cookie attributes (HttpOnly, Secure, SameSite) can help mitigate exploitation risks. Regular security testing, including automated scanning and manual penetration testing focused on XSS vectors, should be integrated into the development lifecycle. User education to recognize phishing attempts leveraging XSS payloads can further reduce successful exploitation.