CVE-2026-42342

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

There exists a potential DOS attack vector in React Router Framework Mode applications (as well as Remix v2.10.0 - 2.17.4). Certain requests can be crafted to consume disproportionate resources on the server, resulting in response time degredation and/or service unavailability for end users.

> [!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 , remix
Affected packages:
@remix-run/css-bundle @ 2.17.0 (+41 more)

Fixes