Intel

AIKIDO-2026-740941

react-router is vulnerable to Deserialization of Untrusted Data

Deserialization of Untrusted Data Pre-CVE
Found by Aikido Intel before public disclosure or CVE publication.
Published 4 days ago

42

Medium Risk

This Affects:

JSreact-router
7.0.0 - 7.17.0
Fixed in 7.18.0
Are you affected? Scan for Free

TL;DR

React Router Framework Mode client hydration previously deserialized server error objects by instantiating arbitrary window[__subType] constructors from serialized metadata. If attacker-influenced error shapes reach hydration data, unsafe constructors can run in the browser. The patch removes the custom deserialization path and routes hydration errors through turbo-stream with a supported error-type whitelist.

Who does this affect?

You are affected if you are using a version that falls within the vulnerable range and running Framework Mode SSR where untrusted data can influence serialized hydration error payloads.

Background info

react-router is vulnerable to Deserialization of Untrusted Data in versions 7.0.0 - 7.17.0.

How to fix this

Upgrade the react-router and/or the react-router-dom library to the patch version.