CVE-2025-46523 is a Stored Cross-site Scripting (XSS) vulnerability classified under CWE-79, affecting the devignstudiosltd product 'COVID-19 (Coronavirus) Update Your Customers' in versions up to 1.5.1. Stored XSS occurs when malicious input is improperly neutralized and then permanently stored by the application, later served to users without adequate sanitization or encoding. This vulnerability allows an attacker to inject malicious scripts into web pages generated by the affected product, which are then executed in the browsers of users who view the compromised content. The flaw arises from insufficient input validation and output encoding during web page generation, enabling attackers to embed arbitrary JavaScript code. Exploitation could lead to session hijacking, credential theft, defacement, or redirection to malicious sites. Although no known exploits are currently reported in the wild, the vulnerability is publicly disclosed and could be targeted by attackers once discovered. The product in question is designed to provide COVID-19 related updates to customers, likely used by organizations to communicate health and safety information. The absence of a patch at the time of disclosure increases the risk window. The vulnerability does not require user authentication to exploit, and user interaction is limited to viewing the malicious content, which is typical for stored XSS attacks. Given the nature of the product, the attack surface includes any organization using this software to disseminate information to clients or employees, potentially exposing a broad user base to malicious scripts.

For European organizations, the impact of this vulnerability can be significant, especially for entities relying on the affected product to communicate critical COVID-19 updates to customers or employees. Successful exploitation could compromise the confidentiality of user credentials and session tokens, leading to unauthorized access to sensitive information or internal systems. Integrity of the communicated information could be undermined by injecting false or misleading content, damaging organizational reputation and trust. Availability is less directly impacted but could be affected if attackers use the vulnerability to launch further attacks such as phishing or malware distribution. Sectors with high reliance on customer communication platforms, such as healthcare providers, public health agencies, and service industries, are particularly at risk. Additionally, given the sensitivity around COVID-19 information, exploitation could cause public panic or misinformation. The medium severity rating reflects the moderate ease of exploitation combined with potentially serious consequences for confidentiality and integrity. The lack of known exploits currently reduces immediate risk but does not preclude future attacks, especially as threat actors often target health-related software during pandemics.

Organizations should implement strict input validation and output encoding on all user-supplied data within the affected product to prevent script injection. Until an official patch is released, deploying web application firewalls (WAFs) with rules targeting common XSS attack patterns can help mitigate exploitation attempts. Administrators should monitor logs for unusual input patterns or suspicious activity related to the product. User education on recognizing phishing or suspicious content is also advisable. If feasible, organizations should consider temporarily disabling or limiting the use of the affected software for public-facing communications. Regularly updating and patching the product once a fix is available is critical. Additionally, applying Content Security Policy (CSP) headers can reduce the impact of XSS by restricting the execution of unauthorized scripts. Conducting security assessments and penetration testing focused on XSS vulnerabilities in the product environment can help identify and remediate weaknesses proactively.