A newly disclosed maximum-severity vulnerability—CVE-2025-55182—affects a large number of modern web applications built with React and Node.js. This flaw enables remote code execution (RCE) on impacted servers and requires immediate mitigation. Below, we summarize what you need to know and how we are already protecting your applications.

What Is React and Why This Vulnerability Matters

React is one of the most widely adopted technologies for building modern web applications. Many enterprise-grade platforms rely on React itself or on frameworks that extend it, such as Next.js. CVE-2025-55182 specifically targets React Server Components (RSC)—a powerful feature used in emerging architectures for rendering and data loading. Because RSC executes on the server, vulnerabilities in this layer pose a high-impact threat to application integrity and sensitive data.

Understanding the Vulnerability (CVE-2025-55182)

This flaw has been assigned a CVSS score of 10.0, the highest possible rating. It enables an unauthenticated attacker to:

• • Bypass security controls

• • Execute arbitrary code on the server

• • Fully compromise the affected application and its data

In other words: this is a critical web application vulnerability that, if exploited, grants attackers complete control over the server.

Are You Affected?

You are likely impacted if your environment uses:

• • React 19.x with React Server Components (RSC)

• • Next.js 15.x or 16.x for server-side or hybrid rendering

• • Node.js applications using RSC-backed logic

If your teams rely on any of these versions, immediate action is required.

Immediate Protection Through Clue Application Protection

If your applications are covered by Clue Application Protection, they already benefit from full, real-time protection against all known exploitation attempts related to CVE-2025-55182. Our protection includes:

Real-Time Zero-Day Defense

Advanced dynamic analysis identifies the malicious patterns associated with this vulnerability and blocks them before they reach your application logic.

Operational Buffer for Safe Patching

This shield reduces the risk of compromise, giving your engineering and platform teams the time they need to apply the permanent vendor patches without rushing or risking service instability.

Required Mitigation: Patch Immediately

Our protection buys time—but patching is still mandatory. Please prioritize these updates as high urgency. Official vendor advisories:

• • React Advisory: https://react.dev/blog/2025/12/03/critical-security-vulnerability-in-react-server-components

• • Next.js Advisory (duplicate tracking, includes patch versions): https://nextjs.org/blog/CVE-2025-66478

You must upgrade your systems to the patched releases listed in these advisories to permanently remove the vulnerability.

Need Support?

If you are unsure whether your application stack uses React Server Components, or if you want to validate your coverage under Clue Application Protection, our team is ready to assist. We will work with you to confirm exposure, verify defenses, and coordinate safe patching across your environments.