# CVE-2026-33245: React Router XSS in unstable RSC redirect handling

Source: https://junglewise.ai/threats/cve-2026-33245-react-router-xss-in-unstable-rsc-redirect-handling  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-02. Updated: 2026-06-03  
License: CC BY 4.0 with a link back

CVE-2026-33245 · Severity: high · CVSS 8 · Published 2026-06-02

React Router, a popular library for managing navigation in web applications, contains a security flaw in its experimental React Server Components (RSC) features. If an application uses these specific experimental tools and processes navigation requests from untrusted sources, an attacker could execute malicious scripts in a user's browser. This could lead to the theft of sensitive session information or unauthorized actions performed on behalf of the user.

Technologies: [React-Router](https://junglewise.ai/threats/technologies/npm-react-router).

## Quick answers

**Is CVE-2026-33245 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-33245 being exploited in the wild.

**How severe is CVE-2026-33245?** High severity, with a CVSS score of 8, published 2 June 2026.

**Which products and versions are affected?** React-Router SEMVER:introduced=7.7.0,fixed=7.13.2.

**Is there a fix for CVE-2026-33245?** Yes. React-Router: upgrade to 7.13.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-33245 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-33245?** Check whether you run React-Router at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- React-Router: upgrade to 7.13.2 or later

## Technical details

A Cross-Site Scripting (XSS) vulnerability exists in React Router v7 when utilizing unstable React Server Components (RSC) APIs. The vulnerability is rooted in the RSC redirect handling logic, which fails to properly neutralize 'javascript:' URI schemes when processing redirect targets from untrusted sources. An attacker can exploit this by providing a malicious redirect URL, leading to client-side script execution in the context of the victim's browser session. This requires the application to be using the experimental RSC features and typically involves user interaction to trigger the malicious redirect. The issue is addressed in version 7.13.2.

## Affected products

- remix-run react-router >= 7.7.0, < 7.13.2

## Identifiers

- CVE-2026-33245
- GHSA-8646-j5j9-6r62

## Timeline

- 2026-06-02: disclosed
- 2026-06-03: advisory
- 2026-06-03: patched: Fixed in version 7.13.2

## References

- [https://api.github.com/users/x4cc3](https://api.github.com/users/x4cc3)
- [https://github.com/x4cc3](https://github.com/x4cc3)
- [https://api.github.com/users/x4cc3/gists%7B/gist_id%7D](https://api.github.com/users/x4cc3/gists%7B/gist_id%7D)
- [https://api.github.com/users/x4cc3/repos](https://api.github.com/users/x4cc3/repos)
- [https://avatars.githubusercontent.com/u/197862569?v=4](https://avatars.githubusercontent.com/u/197862569?v=4)
- [https://api.github.com/users/x4cc3/events%7B/privacy%7D](https://api.github.com/users/x4cc3/events%7B/privacy%7D)

## Related threats

- [remix-run react-router resource consumption in manifest endpoint](https://junglewise.ai/threats/cve-2026-55685-remix-run-react-router-resource-consumption-in-manifest-endpoint)
- [Remix React Router open redirect in Link and useNavigate](https://junglewise.ai/threats/cve-2026-53669-remix-react-router-open-redirect-in-link-and-usenavigate)
- [remix-run React Router improper protocol validation in RSCErrorHandler](https://junglewise.ai/threats/cve-2026-53667-remix-run-react-router-improper-protocol-validation-in)
- [remix-run React Router unsafe reflection in SSR hydration](https://junglewise.ai/threats/cve-2026-53666-remix-run-react-router-unsafe-reflection-in-ssr-hydration)
- [React Router CSRF bypass in RSC mode](https://junglewise.ai/threats/react-router-csrf-bypass-in-rsc-mode-0018662d)