CVE-2026-21884highCWE-79

CVE-2026-21884: high-severity vulnerability in remix-run react-router

React Router SSR XSS in ScrollRestoration

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21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 8.2epss 0.5%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N
Affected products
remix-run · react-router
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