CVE-2026-21884 PUBLISHED

React Router SSR XSS in ScrollRestoration

Assigner: GitHub_M
Reserved: 05.01.2026 Published: 10.01.2026 Updated: 13.01.2026

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 <ScrollRestoration> 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 (<BrowserRouter>) or Data Mode (createBrowserRouter/<RouterProvider>) is being used. This issue has been patched in @remix-run/react version 2.17.3 and react-router version 7.12.0.

Metrics

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

Product Status

Vendor remix-run
Product react-router
Versions
  • Version @remix-run/react < 2.17.3 is affected
  • Version react-router >= 7.0.0, < 7.12.0 is affected

References

Problem Types

  • CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') CWE