React Router vulnerable to Denial of Service via reflected user input in single-fetch
A DoS vulnerability exists in the React Router v7 Framework Mode, as well as Remix v2.9.0+ with Single Fetch enabled. In some scenarios the underlying serialization algorithm can become a bottleneck when encoding specific types of data into server responses. Please upgrade to React Router v7.14.0 or later.
[!NOTE] This does not impact your React Router application if you are using Declarative Mode (
<BrowserRouter>) or Data Mode (createBrowserRouter/<RouterProvider>).
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | react-router | >= 7.0.0, < 7.14.0 | 7.14.0 |
| npm package | turbo-stream | < 3.0.0 | 3.0.0 |
References
- https://github.com/remix-run/react-router/security/advisories/GHSA-rxv8-25v2-qmq8
- https://nvd.nist.gov/vuln/detail/CVE-2026-34077
- https://github.com/remix-run/react-router/commit/59811921d3c7d599077b8cadccdcd65a233165e0
- https://github.com/jacob-ebey/turbo-stream/blob/v2.4.1/src/flatten.ts#L175-L177
- https://github.com/jacob-ebey/turbo-stream/blob/v2.4.1/src/unflatten.ts#L185-L189
- https://github.com/remix-run/react-router
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness (CWE)
CWE-770- Platform
- npm
- Package
react-router, turbo-stream- Disclosed
- 04.06.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-rxv8-25v2-qmq8 - CC BY 4.0
Vulnerability history: react-router
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 20
- First → latest
- 04.2025 07.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 11
- Medium 8
- Low 1
Disclosures per year
- 2025: 2
- 2026: 18
-
React Router vulnerable to Denial of Service via reflected user input in single-fetch this entry
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