Vulnerability Description
React Router is a router for React. In versions 7.0.0 through 7.14.x of react-router and versions 2.10.0 through 2.17.4 of @remix-run/server-runtime, certain crafted requests can consume disproportionate server resources via unbounded path expansion in the __manifest endpoint, resulting in response time degradation and/or service unavailability for end users. This affects React Router Framework Mode applications as well as Remix applications. This does not impact applications using Declarative Mode (`<BrowserRouter>`) or Data Mode (`createBrowserRouter/<RouterProvider>`). This is patched in react-router version 7.15.0 and @remix-run/server-runtime version 2.17.5.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Shopify | React-Router | >= 7.0.0, < 7.15.0 |
| Shopify | Remix-Run\/Server-Runtime | >= 2.10.0, < 2.17.5 |
Related Weaknesses (CWE)
References
FAQ
What is CVE-2026-42342?
CVE-2026-42342 is a vulnerability with a CVSS score of 7.5 (HIGH). React Router is a router for React. In versions 7.0.0 through 7.14.x of react-router and versions 2.10.0 through 2.17.4 of @remix-run/server-runtime, certain crafted requests can consume disproportion...
How severe is CVE-2026-42342?
CVE-2026-42342 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-42342?
Check the references section above for vendor advisories and patch information. Affected products include: Shopify React-Router, Shopify Remix-Run\/Server-Runtime.