React Router: Arbitrary Constructor Injection via deserializeErrors() in React Router SSR Hydration
If application code allows attacker supplied input to overwrite certain aspects of errors caught by the SSR process, then it was possible for attacker to trigger unexpected constructor execution on the client which would trigger outbound network traffic. This is only possible with very specific (and unlikely) application layer code. > [!NOTE] > This does not impact your application if you are using Declarative Mode. This only impacts Framework Mode and Data Mode applications doing manual SSR/hydration
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-53666US | — | — | ||
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 e… | ||||
references
External citations — patches, advisories, analysis.
- https://github.com/remix-run/react-routerPACKAGE
- https://github.com/remix-run/react-router/blob/main/CHANGELOG.md#v7180WEB
- https://github.com/remix-run/react-router/commit/9d22943fd46c8ae4b08236425fa3549e10e9ad1aWEB
- https://github.com/remix-run/react-router/pull/15175WEB
- https://github.com/remix-run/react-router/releases/tag/react-router@7.18.0WEB
- https://github.com/remix-run/react-router/security/advisories/GHSA-337j-9hxr-rhxgWEB
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