CVE-2026-21884

Updated on 10 Jan 2026

Severity

8.2 High severity

Details

CVSS score
8.2
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N

Overview

About vulnerability

React Router is a router for React. In @remix-run/react version prior to 2.17.3. and react-router 7.0.0 through 7.11.0, a XSS vulnerability exists in in React Router’s API in Framework Mode when using the getKey/storageKey props during Server-Side Rendering which could allow arbitrary JavaScript execution during SSR if untrusted content is used to generate the keys. There is no impact if server-side rendering in Framework Mode is disabled, or if Declarative Mode () or Data Mode (createBrowserRouter/) is being used. This issue has been patched in @remix-run/react version 2.17.3 and react-router version 7.12.0.

Details

Affected product:
React , remix
Affected packages:
create-remix @ 2.17.0 (+29 more)
React Router is a router for React. In @remix-run/react version prior to 2.17.3. and react-router 7.0.0 through 7.11.0, a XSS vulnerability exists in in React Router’s API in Framework Mode when using the getKey/storageKey props during Server-Side Rendering which could allow arbitrary JavaScript execution during SSR if untrusted content is used to generate the keys. There is no impact if server-side rendering in Framework Mode is disabled, or if Declarative Mode () or Data Mode (createBrowserRouter/) is being used. This issue has been patched in @remix-run/react version 2.17.3 and react-router version 7.12.0.

Fixes