# CVE-2026-33244: React Router has stored XSS via unescaped Location header in prerendered redirect HTML

> Attackers can inject scripts into pre-rendered HTML via unescaped Location headers in React Router Framework Mode, requiring an upgrade to fix.

- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 2 Jun 2026
- **Updated:** 2 Jun 2026
- **Also known as:** GHSA-f22v-gfqf-p8f3

## What is CVE-2026-33244?

CVE-2026-33244 is a medium-severity cross-site scripting vulnerability in remix-run react-router, published on 2 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

React Router is a router for React. In versions 7.5.1 through 7.13.1, when using Framework Mode with pre-rendering enabled, improper neutralization of the HTTP `Location` header value can permit Cross-Site Scripting (XSS) in the statically generated HTML files if the redirect location comes from an untrusted source. This does not impact applications using Declarative Mode (`<BrowserRouter>`) or Data Mode (`createBrowserRouter/<RouterProvider>`). This is patched in version 7.13.2.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-33244?

2 open source packages ship an affected version, including react-router. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `react-router` | npm | From 7.5.1 | 7.13.2 |
| `react-router` | npm | From 7.5.1 | 7.13.2 |

Products: Shopify React-Router.

## How do I fix CVE-2026-33244?

Upgrade react-router to 7.13.2 or later.

## Is CVE-2026-33244 being exploited?

There is no known exploitation of CVE-2026-33244 in the wild and no public exploit code.

## Other vulnerabilities in remix-run react-router

- [CVE-2026-55685](https://insights.sbomify.com/CVE-2026-55685/): React Router: Unauthenticated Denial of Service via Inefficient Route Matching (high 8.7)
- [CVE-2026-21884](https://insights.sbomify.com/CVE-2026-21884/): React Router SSR XSS in ScrollRestoration (high 8.2)
- [CVE-2026-42211](https://insights.sbomify.com/CVE-2026-42211/): React Router's vendored turbo-stream v2 allows arbitrary constructor invocation via TYPE_ERROR deserialization leading to Unauth RCE (high 8.1)
- [CVE-2026-33245](https://insights.sbomify.com/CVE-2026-33245/): React Router vulnerable to XSS in unstable RSC redirect handling via javascript: redirect targets (high 8.0)
- [CVE-2026-22029](https://insights.sbomify.com/CVE-2026-22029/): React Router vulnerable to XSS via Open Redirects (high 8.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33244 and fix it if it is affected.

What it is: CVE-2026-33244 is a medium-severity cross-site scripting vulnerability in remix-run react-router, published on 2 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-33244 in the wild and no public exploit code.

Affected packages and fixed versions:
- react-router (npm): affected from 7.5.1; fixed in 7.13.2
- react-router (npm): affected from 7.5.1; fixed in 7.13.2

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-33244/ (Markdown: https://insights.sbomify.com/CVE-2026-33244/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33244
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33244
- OSV: https://osv.dev/vulnerability/CVE-2026-33244

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33244/
Summaries are generated and may contain mistakes; the official description above is the record.