URGENT: Critical Security Vulnerability in React 19 and Next.js 15/16

A critical security vulnerability (CVE-2025-55182) has been discovered in React Server Components, affecting React 19.x and Next.js 15.x/16.x applications. This remote code execution vulnerability requires immediate patching.

Affected Versions:

  • React: All versions of React 19.x prior to 19.1.0
  • Next.js: Versions 15.x and 16.x with App Router enabled

Immediate Action Required:

  • React 19: Upgrade to version 19.1.0 or later
  • Next.js 15: Upgrade to latest patched versions

This vulnerability allows unauthenticated remote code execution and has already been exploited by threat actors. Treat this as a critical security incident.