Description
React Router is a router for React. In versions 6.4.0 through 7.17.0, if application code was written in a way that allows attacker-supplied input to overwrite certain aspects of errors caught by the SSR process, then it was possible for an attacker to trigger unexpected constructor execution on the client, which would in turn trigger an outbound network request. This is only possible with very specific (and unlikely) application-layer code. Note that this does not impact an application if it is using Declarative Mode. It only impacts Framework Mode and Data Mode applications that perform manual SSR/hydration. This issue has been fixed in version 7.18.0.
Affected products
shopify: react-router
References5
- github.com/remix-run/react-router/commit/9d22943fd46c8ae4b08236… Patch
- github.com/remix-run/react-router/pull/15175 Issue TrackingPatch
- github.com/remix-run/react-router/blob/main/CHANGELOG.md#v7180 Release Notes
- github.com/remix-run/react-router/releases/tag/[email protected]… Release Notes
- github.com/remix-run/react-router/security/advisories/GHSA-337j… Third Party Advisory
Metrics
- CVSS 3.1
-
6.1
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 37 · as of 13 November 2026
- CWE
- CWE-470
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.