CVE-2026-21884
React Router SSR XSS in ScrollRestoration
- State
- Published
- Severity
- 8.2 High
- Published
- Jan 10, 2026
- Updated
- Jul 15, 2026
- Reserved
- Jan 5, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 8.2 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N | GitHub_M |
| 3.1 | 8.2 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N | redhat-SADP |
Weaknesses
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Products
| Product | Versions |
|---|---|
react-routerremix-run |
|
References
- https://github.com/remix-run/react-router/security/advisories/GHSA-8v8x-cx79-35w7
- https://access.redhat.com/security/cve/CVE-2026-21884vdb-entry
- RHBZ#2428421issue-tracking
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-21884.json
- https://access.redhat.com/errata/RHSA-2026:3958vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3960vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3782vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:19712vendor-advisory
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