React Router is a router for React. From 7.12.0 until 7.15.1, certain CSRF checks in React Router v7 Framework Mode were insufficient and run on POST requests, but were bypassed on PUT/PATCH/DELETE requests. This is a low severity vulnerability because modern browser protections (CORS preflight, SameSite cookies) already block the cross-origin attack vectors that this missing CSRF check would otherwise gate. This vulnerability is fixed in 7.15.1.