Urgent: Next.js CVE-2025-66478 Vulnerability: What You Need to Know and Do Now A critical flaw has put Next.js applications using React Server Components (RSC) and the App Router at serious risk. This vulnerability, identified as CVE-2025-66478 and scoring a maximum 10.0 on the ... CVE-2025-66478 Next.js patching React Server Components remote code execution security vulnerability