CVE-2026-21884 HIGH

CVE-2026-21884: React Router SSR XSS in ScrollRestoration

Vendor Remix-Run
Product react-router
Weakness CWE-79 · XSS
Published January 10, 2026
Last update June 30, 2026
View on NVD All CVEs

CVSS base score

8.2/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Confidentiality High
Integrity Low

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

January 10, 2026 CVE published
June 30, 2026 Record updated