CVE-2026-55685

React Router: Unauthenticated Denial of Service via Inefficient Route Matching

Description

React Router is a router for React. In versions 7.0.0 through 7.17.0, the manifest endpoint could be accessed via unauthenticated targeted requests that would put heavy load on the server and slow down response times. This issue is a follow up to CVE-2026-42342, and does not does not impact React Router applications using Declarative Mode (<BrowserRouter>) or Data Mode (createBrowserRouter/<RouterProvider>). This issue has been fixed in version 7.18.0.

Scores

Weaknesses (CWE)

• CWE-400
• CWE-407

Advisories

• GHSA-chx6-hx7r-mcp5 — React Router: Unauthenticated Denial of Service via Inefficient Route Matching

European references

• ENISA EUVD · EUVD-2026-49634
• GCVE · GCVE-0-2026-55685

CERT-FR advisories

• CERTFR-2026-AVI-1291 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr

Affected configurations (NVD CPE)

• cpe:2.3:a:shopify:react-router:*:*:*:*:*:node.js:*:* ≥ 7.0.0 < 7.18.0

Affected products

References

• https://github.com/remix-run/react-router/security/advisories/GHSA-chx6-hx7r-mcp5
• https://github.com/remix-run/react-router/security/advisories/GHSA-8x6r-g9mw-2r78
• https://github.com/remix-run/react-router/pull/15186
• https://github.com/remix-run/react-router/commit/09e6020d1950e54f361f7ad00938ecd4dde60929
• https://github.com/remix-run/react-router/blob/main/CHANGELOG.md#v7180
• https://github.com/remix-run/react-router/releases/tag/react-router@7.18.0

Sources