CVE-2026-21884
HIGH8.2EPSS 0.02%React Router SSR XSS in ScrollRestoration
Published: 1/8/2026Modified: 2/3/2026
Description
A XSS vulnerability exists in in React Router's `<ScrollRestoration>` API in [Framework Mode](https://reactrouter.com/start/modes#framework) 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. > [!NOTE] > This does not impact applications if developers have [disabled server-side rendering](https://reactrouter.com/how-to/spa) in Framework Mode, or if they are using [Declarative Mode](https://reactrouter.com/start/modes#declarative) (`<BrowserRouter>`) or [Data Mode](https://reactrouter.com/start/modes#data) (`createBrowserRouter`/`<RouterProvider>`).
Affected packages (2)
- npm/react-router>= 7.0.0, < 7.12.0
- npm/@remix-run/reactfrom 0, < 2.17.3
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N |