p PatchFirst

CVE-2026-53666

CVE-2026-53666 · React Router: Arbitrary Constructor Injection via deserializeErrors() in React Router SSR Hydration

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 6.1 · Medium · EPSS 0.4% · Fix available

Published
Updated

Stack: node

Affected products and versions

  • react-router

    Versions
    • >= 6.4.0, < 7.18.0: Affected

    No fix published

  • react-router npm

    Affected ranges
    • SEMVER: ≥ 6.4.0, < 7.18.0

    Update to 7.18.0

Original sources

Check your server →