Solved: Critical RSC Vulnerability in Next.js & React 19. Here's the Fix.

🚀 Executive Summary TL;DR: A critical Remote Code Execution (RCE) vulnerability has been identified in the React Server Components (RSC) “Flight” protocol, primarily affecting Next.js applications through malicious payload deserialization. The immediate solution involves upgrading Next.js, React, and react-dom dependencies to their latest patched versions, complemented by proactive automated dependency scanning in CI/CD pipelines. 🎯 Key Takeaways The vulnerability is a Remote Code Execution (RCE) rooted in the React Server Components (RSC) “Flight” protocol, specifically during the deserialization of client-sent data within Server Actions. Immediate remediation requires upgrading Next.js to patched versions (e.g., 14.2.0 for 14.1.1-14.1.4, or 14.1.1 for 14.0.0-14.1.0) along with react@latest and react-dom@latest . Long-term prevention involves implementing automated dependency scanning tools like GitHub’s Dependabot, Snyk, or Renovate Bot within CI/CD pipelines to detect and patch vuln