CVE-2026-34077 HIGH

CVE-2026-34077: React Router vulnerable to Denial of Service via reflected user input in single-fetch

Vendor Remix-Run
Product react-router
Weakness CWE-770 · Uncontrolled resource consumption
Published June 2, 2026
Last update June 3, 2026
View on NVD All CVEs

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

June 2, 2026 CVE published
June 3, 2026 Record updated