CVE-2026-53666

MEDIUM

MEDIUM Priority: 0.03 BB Relevance: 62/100

Published: 2026-07-27 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth Scope Change

CVSS Vector Breakdown

AV: Network

AC: Low

PR: None

UI: Required

S: Changed

C: Low

I: Low

A: None

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.