CVE-2025-49064 is a high-severity reflected Cross-site Scripting (XSS) vulnerability affecting the Webilop User Language Switch component, versions up to 1.6.10. The vulnerability arises from improper neutralization of user input during web page generation, specifically in the language switch functionality. This allows an attacker to inject malicious scripts that are reflected back to the user without proper sanitization or encoding. The vulnerability is exploitable remotely over the network without requiring authentication, but it does require user interaction, such as clicking a crafted link or visiting a maliciously crafted URL. The CVSS 3.1 base score of 7.1 reflects the high impact on confidentiality, integrity, and availability, as the vulnerability can lead to session hijacking, credential theft, or execution of arbitrary scripts in the context of the victim's browser. The scope is changed (S:C), indicating that exploitation can affect components beyond the vulnerable module, potentially compromising the entire web application or user session. No known exploits are currently reported in the wild, and no patches have been linked yet, indicating that mitigation may rely on vendor updates or manual input validation improvements. The vulnerability is categorized under CWE-79, which is a common and well-understood web application security flaw related to improper input validation and output encoding.

For European organizations using Webilop User Language Switch, this vulnerability poses a significant risk to web application security. Exploitation could lead to unauthorized access to user sessions, theft of sensitive data, and potential spread of malware through script injection. This is particularly critical for organizations handling personal data under GDPR, as a successful attack could result in data breaches and regulatory penalties. The reflected XSS nature means phishing campaigns could be enhanced by embedding malicious scripts in URLs, increasing the risk of social engineering attacks targeting employees or customers. Additionally, the vulnerability could undermine trust in affected web services, impacting business reputation and customer confidence. Given the cross-site scripting can affect confidentiality, integrity, and availability, organizations may face operational disruptions and financial losses. The lack of patches at the time of disclosure necessitates immediate attention to reduce exposure.

European organizations should implement the following specific mitigations: 1) Apply any vendor-provided patches or updates as soon as they become available. 2) In the interim, implement strict input validation and output encoding on the language switch parameters to neutralize potentially malicious input. Use context-aware encoding libraries that handle HTML, JavaScript, and URL contexts appropriately. 3) Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of XSS attacks. 4) Conduct thorough code reviews and penetration testing focusing on the language switch functionality to identify and remediate similar input handling issues. 5) Educate users and staff about the risks of clicking on suspicious links, especially those involving language or localization parameters. 6) Monitor web server logs and intrusion detection systems for unusual requests targeting the language switch endpoint. 7) Consider implementing web application firewalls (WAFs) with rules designed to detect and block reflected XSS payloads targeting this component.