CVE-2026-23870
Facebook React has a Denial of Service Vulnerability in React Server Components
Description
## Impact A denial of service vulnerability could be triggered by sending specially crafted HTTP requests to server function endpoints, this could lead to out-of-memory exceptions or excessive CPU usage. We recommend updating immediately. The vulnerability exists in versions 19.0.0 through 19.0.5, 19.1.0 through 19.1.6, and 19.2.0 through 19.2.5 of: [react-server-dom-webpack](https://www.npmjs.com/package/react-server-dom-webpack) [react-server-dom-parcel](https://www.npmjs.com/package/react-server-dom-parcel) [react-server-dom-turbopack](https://www.npmjs.com/package/react-server-dom-turbopack?activeTab=readme) ## Patches Fixes were back ported to versions 19.0.6, 19.1.7, and 19.2.6. If you are using any of the above packages please upgrade to any of the fixed versions immediately. If your app’s React code does not use a server, your app is not affected by this vulnerability. If your app does not use a framework, bundler, or bundler plugin that supports React Server Components, your app is not affected by this vulnerability. References See the [blog post](https://react.dev/blog/2025/12/11/denial-of-service-and-source-code-exposure-in-react-server-components) for more information and upgrade instructions.
How to fix CVE-2026-23870
To remediate CVE-2026-23870, upgrade the affected package to a fixed version below.
- —upgrade to 19.0.6 or later
- —upgrade to 19.0.6 or later
- —upgrade to 19.0.6 or later
Is CVE-2026-23870 being exploited?
Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.