CVE-2025-55346 is a critical security vulnerability classified under CWE-94, which pertains to improper control of code generation, commonly known as code injection. This vulnerability arises from the unsafe use of a dynamic Function constructor in JavaScript, where user-controlled input is directly passed without proper sanitization or validation. An attacker can exploit this flaw by sending a crafted POST request containing malicious JavaScript code. Because the vulnerable implementation executes this code unsandboxed within the host's context, the attacker gains the ability to run arbitrary JavaScript commands with the same privileges as the host application. This can lead to complete compromise of the affected system, including unauthorized data access, manipulation, and disruption of service. The CVSS v3.1 score of 9.8 (critical) reflects the vulnerability's high impact on confidentiality, integrity, and availability, combined with its ease of exploitation (network attack vector, no privileges or user interaction required). Although no known exploits are currently reported in the wild, the simplicity of exploitation and severity make it a significant threat. The affectedVersions field is ambiguous ('0'), suggesting either a placeholder or a zero-day affecting an unspecified or broad range of versions, which requires immediate attention from organizations using JavaScript environments or frameworks that utilize dynamic Function constructors unsafely.

For European organizations, the impact of CVE-2025-55346 could be severe. Since the vulnerability allows remote attackers to execute arbitrary code without authentication or user interaction, it could lead to widespread compromise of web applications, backend services, or any system executing vulnerable JavaScript code. This could result in data breaches involving sensitive personal data protected under GDPR, leading to regulatory penalties and reputational damage. Critical infrastructure providers, financial institutions, and public sector entities in Europe that rely on JavaScript-based platforms or microservices could face operational disruptions, data integrity issues, and potential lateral movement by attackers within their networks. The vulnerability's ability to fully compromise confidentiality, integrity, and availability makes it a high-risk threat that could facilitate espionage, ransomware deployment, or service outages, impacting business continuity and trust.

To mitigate CVE-2025-55346, European organizations should immediately audit their codebases and dependencies for unsafe usage of dynamic Function constructors or similar code generation methods that incorporate user input. Replace dynamic Function constructors with safer alternatives such as static code or well-validated input parsing. Implement strict input validation and sanitization to ensure no untrusted data reaches code evaluation functions. Employ Content Security Policy (CSP) headers to restrict execution of inline scripts and reduce the impact of injected code. Use runtime application self-protection (RASP) tools to detect and block suspicious code execution patterns. Regularly update and patch all JavaScript frameworks and libraries once vendors release fixes. Conduct penetration testing focused on code injection vectors. Additionally, implement network-level protections such as Web Application Firewalls (WAFs) with rules targeting suspicious POST requests containing executable code patterns. Finally, establish monitoring and alerting for anomalous JavaScript execution or unexpected outbound connections that may indicate exploitation attempts.