CVE-2025-55182 is a critical vulnerability affecting Meta's React Server Components, specifically versions 19.0.0, 19.1.0, and 19.2.0, including the react-server-dom-parcel, react-server-dom-turbopack, and react-server-dom-webpack packages. The root cause is unsafe deserialization of untrusted data (CWE-502) in HTTP requests directed at Server Function endpoints. Deserialization is the process of converting data from a format suitable for transmission or storage back into an object or data structure. When this process is performed on untrusted input without proper validation or sanitization, it can lead to arbitrary code execution. In this case, attackers can craft malicious payloads that, when deserialized by the vulnerable server components, execute arbitrary code remotely. The vulnerability requires no authentication or user interaction, making it highly exploitable over the network. The CVSS v3.1 score of 10.0 reflects the critical nature, with attack vector network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and complete impact on confidentiality (C:H), integrity (I:H), and availability (A:H). Although no active exploits have been reported, the vulnerability's characteristics make it a prime target for attackers. The affected packages are widely used in modern React-based server-side rendering and server component architectures, which are increasingly adopted in web applications for performance and scalability. The lack of available patches at the time of publication increases the urgency for organizations to implement interim mitigations and monitor for suspicious activity.

For European organizations, the impact of CVE-2025-55182 is severe. Organizations using vulnerable versions of Meta's React Server Components in their web applications risk full compromise of affected servers. This includes potential data breaches, unauthorized access to sensitive information, defacement, service disruption, and lateral movement within networks. The vulnerability's remote code execution capability without authentication or user interaction means attackers can exploit it at scale, potentially targeting critical infrastructure, e-commerce platforms, government portals, and financial services that rely on React Server Components for dynamic content delivery. The confidentiality, integrity, and availability of affected systems are all at risk, which can lead to regulatory non-compliance under GDPR due to data breaches or service outages. The ease of exploitation and the high prevalence of React-based applications in Europe amplify the threat. Additionally, the lack of active exploits currently does not reduce risk, as threat actors may develop exploits rapidly given the vulnerability's severity.

1. Immediate upgrade: Organizations should monitor Meta's official channels for patches or updates addressing CVE-2025-55182 and apply them as soon as they become available. 2. Temporary workarounds: Until patches are released, restrict access to Server Function endpoints by implementing strict network controls such as IP whitelisting, VPN-only access, or web application firewalls (WAF) with custom rules to detect and block suspicious deserialization payloads. 3. Input validation: Implement additional server-side validation and sanitization of all incoming data to Server Function endpoints to prevent malicious payloads from being processed. 4. Monitoring and detection: Deploy enhanced logging and anomaly detection focused on deserialization activities and unusual HTTP request patterns targeting Server Function endpoints. 5. Code review: Audit application code that integrates with react-server-dom packages to identify unsafe deserialization practices and refactor to safer alternatives if possible. 6. Incident response readiness: Prepare for potential exploitation by updating incident response plans, ensuring backups are current, and isolating vulnerable systems if compromise is suspected. 7. Developer awareness: Educate development teams on the risks of unsafe deserialization and secure coding practices to prevent similar vulnerabilities in the future.