CVE-2026-33244CWE-79

React Router has stored XSS via unescaped Location header in prerendered redirect HTML

Medium · published June 2, 2026

CVSS v3.1
5.4
EPSS
0%
Percentile
3.4
In the wild
Unconfirmed
What it is

React Router is a router for React. In versions 7.5.1 through 7.13.1, when using Framework Mode with pre-rendering enabled, improper neutralization of the HTTP `Location` header value can permit Cross-Site Scripting (XSS) in the statically generated HTML files if the redirect location comes from an untrusted source. This does not impact applications using Declarative Mode (`<BrowserRouter>`) or Data Mode (`createBrowserRouter/<RouterProvider>`). This is patched in version 7.13.2.

The record
Technical detail
CVSS v3.1
5.4 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00144 · 3.4th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-06-02T16:59Z
EPSS history
Timeline
  • 02 JUN 16:59Z
    React Router has stored XSS via unescaped Location header in prerendered redirect HTML
    cvelistv5