# CVE-2026-33244: React Router XSS in Framework Mode pre-rendering

Source: https://junglewise.ai/threats/cve-2026-33244-react-router-xss-in-framework-mode-pre-rendering  
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-2026-33244 · Severity: medium · CVSS 5.4 · Published 2026-06-02

React Router is a popular library used to manage navigation in web applications. A security flaw exists when the library is used in 'Framework Mode' with pre-rendering enabled, where it fails to properly clean redirect information. This could allow an attacker to inject malicious scripts into the website, potentially leading to unauthorized actions or data theft from users visiting the affected pages.

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

## Quick answers

**Is CVE-2026-33244 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-33244 being exploited in the wild.

**How severe is CVE-2026-33244?** Medium severity, with a CVSS score of 5.4, published 2 June 2026.

**Which products and versions are affected?** React-Router SEMVER:introduced=7.5.1,fixed=7.13.2.

**Is there a fix for CVE-2026-33244?** 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-2026-33244 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-33244?** 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 stored Cross-Site Scripting (XSS) vulnerability exists in React Router v7 when using Framework Mode with Pre-rendering enabled. The vulnerability stems from improper neutralization of the HTTP 'Location' header value during the generation of static redirect HTML files. If a redirect destination is derived from an untrusted source, an attacker can inject malicious scripts into the pre-rendered HTML. This issue specifically affects statically generated files and does not impact applications using Declarative Mode or Data Mode. The vulnerability is addressed in version 7.13.2.

## Affected products

- remix-run react-router >= 7.5.1, < 7.13.2

## Identifiers

- CVE-2026-33244
- GHSA-f22v-gfqf-p8f3

## 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/yuito-it](https://api.github.com/users/yuito-it)
- [https://github.com/yuito-it](https://github.com/yuito-it)
- [https://api.github.com/users/yuito-it/gists%7B/gist_id%7D](https://api.github.com/users/yuito-it/gists%7B/gist_id%7D)
- [https://api.github.com/users/yuito-it/repos](https://api.github.com/users/yuito-it/repos)
- [https://avatars.githubusercontent.com/u/132048482?v=4](https://avatars.githubusercontent.com/u/132048482?v=4)
- [https://api.github.com/users/yuito-it/events%7B/privacy%7D](https://api.github.com/users/yuito-it/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)