CVE-2026-40181

React Router's same-origin redirect with path starting // causes open redirect via protocol-relative URL reinterpretation

Published: 6/3/2026Modified: 6/3/2026
Also known as:GHSA-2j2x-hqr9-3h42

Description

Certain URLs passed to the `redirect` function can trigger an open redirect to an external domain depending on the level of validation done by the application prior to returning the `redirect`. > [!NOTE] > This does not impact your React Router application if you are using [Declarative Mode](https://reactrouter.com/start/modes#declarative) (`<BrowserRouter>`)

Affected packages (1)

CVSS scores

SourceVersionSeverityVector
osvCVSS 4.0CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U

References (3)