Critical React2Shell RCE Hits React and Next.js (CVE-2025-55182 / CVE-2025-66478)
React2Shell is a severe remote, unauthenticated RCE vulnerability recently uncovered in React Server Components (RSC) and the Next.js App Router — tracked as CVE-2025-55182, with CVE-2025-66478 later merged as a duplicate — that allows attackers to execute arbitrary code on servers by exploiting insecure Flight protocol deserialization (CWE-502), earning the flaw a maximum CVSS score of 10.0.