CVE-2026-33244

Updated on 02 Jun 2026

Severity

5.4 Medium severity

Details

CVSS score
5.4
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Overview

About vulnerability

When using React Router v7 [Framework Mode](https://reactrouter.com/start/modes#framework) with [Pre-rendering](https://reactrouter.com/how-to/pre-rendering) enabled, an improper neutralization of the HTTP Location header value can permit Cross-Site Scripting (XSS) in statically generated HTML files if the redirect location comes from an untrusted source.

> [!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
Affected packages:
create-react-router @ 7.5.1 (+22 more)