React2Shell(CVE-2025-55182): Critical RCE Vulnerability in React Server Components and Next.js
The modern JavaScript ecosystem was shaken this week as Meta, Vercel, Google Cloud, AWS, and leading security researchers revealed two critical issues: CVE-2025-55182 and the downstream Next.js variant CVE-2025-66478. Both are rated CVSS 10 and allow remote code execution (RCE) by exploiting weaknesses in the React Server Components (RSC) “Flight” protocol. The vulnerabilities affect React 19 and all major frameworks embedding the RSC implementation, most notably Next.js 15.x and 16.x.