high7.5
CVE-2025-31137
Remix and React Router allow URL manipulation via Host / X-Forwarded-Host headers
Impact
### Impact We received a report about a vulnerability in Remix/React Router that affects all Remix 2 and React Router 7 consumers using the Express adapter. Basically, this vulnerability allows anyone to spoof the URL used in an incoming `Request` by putting a URL pathname in the port section of a URL that is part of a `Host` or `X-Forwarded-Host` header sent to a Remix/React Router request handler. ### Patches This issue has been patched and released in Remix 2.16.3 React Router 7.4.1. ### Credits - Rachid Allam (zhero;) - Yasser Allam (inzo_)
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | @react-router/express | >= 7.0.0, < 7.4.1 | 7.4.1 |
| npm | @remix-run/express | >= 2.11.1, < 2.16.3 | 2.16.3 |