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

Published Jan 8, 2026
·
Updated

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.

> [!NOTE] > This does not impact applications if developers have disabled server-side rendering in Framework Mode, or if they are using Declarative Mode (<BrowserRouter>) or Data Mode (createBrowserRouter/<RouterProvider>).

Other sources

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.

— NVD

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.

— IBM

Affected Software

5 affected componentsFixes available
npm/@remix-run/react<2.17.3
2.17.3
npm/react-router>=7.0.0<7.12.0
7.12.0
Shopify React-router Node.js>=7.0.0<=7.11.0
Shopify Remix-run\/react Node.js<2.17.3
IBM watsonx.data intelligence<=5.2.0, 5.2.1, 5.3.0, 5.3.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade npm/@remix-run/react to a version that resolves this vulnerability.

    Fixed in 2.17.3
  2. Upgrade

    Upgrade npm/react-router to a version that resolves this vulnerability.

    Fixed in 7.12.0
  3. Upgrade

    Upgrade @remix-run/react to a version that resolves this vulnerability.

    Fixed in 2.17.3
  4. Upgrade

    Upgrade react-router to a version that resolves this vulnerability.

    Fixed in 7.12.0

Event History

Jan 8, 2026
Advisory Published
via GitHub·08:50 PM
Data Sourced
via GitHub·08:50 PM
DescriptionSeverityWeaknessAffected Software
Jan 10, 2026
CVE Published
via MITRE·02:41 AM
Data Sourced
via MITRE·02:41 AM
DescriptionSeverityWeakness
Data Sourced
via NVD·03:15 AM
DescriptionSeverityWeakness
Data Sourced
via NVD·03:15 AM
Affected Software
Data Sourced
via Red Hat·04:02 AM
DescriptionSeverityAffected Software
Apr 27, 2026
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2026-21884?

CVE-2026-21884 is classified as a Cross-Site Scripting (XSS) vulnerability affecting React Router's ScrollRestoration API.

2

How do I fix CVE-2026-21884?

To mitigate CVE-2026-21884, upgrade to @remix-run/react version 2.17.3 or react-router version 7.12.0.

3

What software packages are affected by CVE-2026-21884?

CVE-2026-21884 affects @remix-run/react versions below 2.17.3 and react-router versions between 7.0.0 and 7.12.0.

4

Can CVE-2026-21884 lead to arbitrary JavaScript execution?

Yes, CVE-2026-21884 can allow arbitrary JavaScript execution during Server-Side Rendering if untrusted content is used.

5

Is CVE-2026-21884 related to Server-Side Rendering?

Yes, CVE-2026-21884 specifically impacts the Server-Side Rendering process of React Router's ScrollRestoration API.

Company

Resources

Contact

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