CVE-2025-49412 is a medium severity vulnerability classified under CWE-79, which corresponds to Improper Neutralization of Input During Web Page Generation, commonly known as Cross-site Scripting (XSS). This vulnerability affects the 'Page Transition' product developed by numixtech, specifically versions up to 1.3. The flaw allows an attacker to inject malicious scripts that are stored persistently on the affected web application. When other users access the compromised pages, the malicious script executes in their browsers, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the user. The CVSS 3.1 vector indicates that the attack can be executed remotely over the network (AV:N) with low attack complexity (AC:L), but requires high privileges (PR:H) and user interaction (UI:R). The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. The impact on confidentiality, integrity, and availability is low to medium (C:L/I:L/A:L). No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was published on August 20, 2025, and was reserved in early June 2025. Stored XSS vulnerabilities are particularly dangerous because they can affect multiple users and persist over time, making them attractive targets for attackers aiming to compromise user accounts or spread malware via trusted websites.

For European organizations, this vulnerability poses a moderate risk especially for those using or integrating the numixtech Page Transition product in their web infrastructure. Exploitation could lead to unauthorized access to user sessions, data leakage, and manipulation of web content, undermining user trust and potentially violating data protection regulations such as GDPR. The requirement for high privileges to exploit somewhat limits the attack surface, but insider threats or compromised accounts could still leverage this vulnerability. The persistent nature of stored XSS increases the risk of widespread impact across users. Organizations in sectors with high web interaction, such as e-commerce, finance, and public services, could face reputational damage and regulatory penalties if exploited. Additionally, the cross-site scripting could be used as a vector for delivering further malware or phishing attacks targeting European users.

Given the absence of an official patch, European organizations should implement immediate compensating controls. These include rigorous input validation and output encoding on all user-supplied data within the Page Transition application to neutralize malicious scripts. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of XSS attacks. Conduct thorough code reviews focusing on areas where user input is reflected or stored. Limit the number of users with high privileges to minimize exploitation risk. Monitor web application logs for unusual activity indicative of XSS exploitation attempts. Additionally, implement web application firewalls (WAF) with rules tuned to detect and block XSS payloads targeting the affected product. Organizations should also prepare for rapid deployment of patches once available and consider isolating or restricting access to vulnerable components until remediation is complete.