---
id: CVE-2026-53667
aliases:
  - GHSA-h8fp-f39c-q6mh
title: 'React Router: RSCErrorHandler Missing Protocol Validation (XSS)'
summary: 'React Router: RSCErrorHandler Missing Protocol Validation (XSS)'
severity: medium
cvss: 6.9
cwe:
  - CWE-79
vendor: react-router
product: react-router
ecosystem: npm
affected:
  - 'react-router >= 7.11.0, < 7.18.0'
patched:
  - react-router 7.18.0
published: '2026-07-23'
updated: '2026-07-23'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-h8fp-f39c-q6mh'
references:
  - url: >-
      https://github.com/remix-run/react-router/security/advisories/GHSA-h8fp-f39c-q6mh
  - url: 'https://github.com/remix-run/react-router/pull/15177'
  - url: >-
      https://github.com/remix-run/react-router/commit/ce596e823f0d7b883a433af1d5a839a8b9fe0242
  - url: 'https://github.com/remix-run/react-router/blob/main/CHANGELOG.md#v7180'
  - url: 'https://github.com/remix-run/react-router/releases/tag/react-router@7.18.0'
  - url: 'https://github.com/advisories/GHSA-h8fp-f39c-q6mh'
tags:
  - ghsa
  - npm
ingestedAt: '2026-07-23T20:19:19.548Z'
epss: 0.00355
epssPercentile: 0.26572
---

## Overview

This is a follow up to https://github.com/remix-run/react-router/security/advisories/GHSA-8646-j5j9-6r62.  React Router was alerted of a code path in the (unstable) RSC error handling path in which redirects from untrusted sources could still result in an XSS vector via attacker-supplied redirect targets

> [!NOTE]
> This only affects your application if you are using the unstable RSC APIs

## Affected packages

- `react-router >= 7.11.0, < 7.18.0`

## Remediation

Upgrade to a patched release:

- `react-router 7.18.0`