Critical RSC Deserialization Flaw in React and Next.js
🚨 A maximum-severity remote code execution vulnerability in React Server Components (CVE-2025-55182, CVSS 10.0) allows unauthenticated attackers to execute arbitrary JavaScript by sending crafted payloads to Server Function endpoints. Affected npm packages include react-server-dom-webpack, react-server-dom-parcel, and react-server-dom-turbopack in specific 19.x releases; fixes are available in 19.0.1, 19.1.2, and 19.2.1. The issue also impacts Next.js (CVE-2025-66478, CVSS 10.0) across multiple releases and has been patched in a series of 15.x and 16.x updates. Security firm Wiz reports roughly 39% of cloud environments host vulnerable instances; apply patches immediately.
