CVE-2026-34077

Updated on 02 Jun 2026

Severity

7.5 High severity

Details

CVSS score
7.5
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Overview

About vulnerability

A DoS vulnerability exists in the React Router v7 [Framework Mode](https://reactrouter.com/start/modes#framework), as well as Remix v2.9.0+ with [Single Fetch](https://v2.remix.run/docs/guides/single-fetch) enabled. In some scenarios the underlying serialization algorithm can become a bottleneck when encoding specific types of data into server responses. Please upgrade to React Router v7.14.0 or later.

> [!NOTE] > This does not impact your React Router application if you are using [Declarative Mode](https://reactrouter.com/start/modes#declarative) (<BrowserRouter>) or [Data Mode](https://reactrouter.com/start/modes#data) (createBrowserRouter/<RouterProvider>).

Details

Affected product:
React , turbo-stream
Affected packages:
create-react-router @ 7.5.1 (+11 more)