CVE-2026-21884

CVSS 8.2 HighEPSS 0.0%
  • CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N
  • Published: 2026-01-10T03:15:48.673

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 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 () or Data Mode (createBrowserRouter/) is being used. This issue has been patched in @remix-run/react version 2.17.3 and react-router version 7.12.0.

Related CVE by CWE

No related CWE found.

Top CVE for Vendor

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Recently Exploited Similar Vulnerabilities

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How to fix CVE-2026-21884

CVE-2026-21884 is a high severity vulnerability affecting the affected product.

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 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. […]

Exploit Difficulty: MEDIUM
⏱️ Time to exploit: 1-4 hours
🛠️ Required skills: Intermediate security knowledge
💰 Public exploits: May be available

How to Fix:

1 Identify affected systems

- Check if you're running the affected product

2 Immediate actions

- Update to the latest patched version
- If patching is not immediately possible: restrict network exposure, apply least-privilege access

3 Verification

- Test the fix in a staging environment first
- Review logs for signs of exploitation
- Monitor for IOCs (Indicators of Compromise)

4 Long-term prevention

- Enable automatic security updates
- Set up vulnerability monitoring
- Review and harden security configurations

Exploit Difficulty Assessment

MEDIUM
⏱️ Time to Exploit: 1-4 hours
🛠️ Skills Required: Intermediate security knowledge
💰 Public Exploits: May be available

Vulnerability Timeline

Jan 10, 2026
Vulnerability Published

CVE details first published to NVD database

Jan 10, 2026
Imported to Database

Added to this CVE tracking system

Detection Rules & IOCs

No specific detection rules generated for this vulnerability type.

No vendor/product data available.