CVE-2026-42342
React Router vulnerable to DoS via unbounded path expansion in __manifest endpoint
Description
There exists a potential DOS attack vector in React Router Framework Mode applications (as well as Remix v2.10.0 - 2.17.4). Certain requests can be crafted to consume disproportionate resources on the server, resulting in response time degredation and/or service unavailability for end users. > [!NOTE] > This does not impact your React Router application if you are using [Declarative Mode](https://reactrouter.com/start/modes#declarative) (`<BrowserRouter>`) or [Data Mode](https://reactrouter.com/start/modes#data) (`createBrowserRouter`/`<RouterProvider>`).
How to fix CVE-2026-42342
To remediate CVE-2026-42342, upgrade the affected package to a fixed version below.
- —upgrade to 7.15.0 or later
- —upgrade to 2.17.5 or later
Is CVE-2026-42342 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- >= 7.0.0, < 7.15.0
- >= 2.10.0, < 2.17.5
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |