CVE-2026-34077CWE-770

React Router vulnerable to Denial of Service via reflected user input in single-fetch

High · published June 2, 2026

CVSS v3.1
7.5
EPSS
0%
Percentile
38.3
In the wild
Unconfirmed
What it is

React Router is a router for React. In versions 7.7.0 through 7.13.1, when using React Router's unstable React Server Components (RSC) APIs, there is a potential client-side Cross-Site Scripting (XSS) vulnerability in the RSC redirect handling if redirects come from untrusted sources. This does not impact applications that are not using the unstable RSC APIs in React Router. This is patched in version 7.13.2.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00453 · 38.3th percentile
Weakness
CWE-770 · Allocation of Resources Without Limits or Throttling
Published
2026-06-02T17:31Z
EPSS history
Timeline
  • 02 JUN 17:31Z
    React Router vulnerable to Denial of Service via reflected user input in single-fetch
    cvelistv5