GHSA-mx8g-39q3-5c79 webpack-dev-server vulnerable to HMR WebSocket interception via permissive user proxies

• npm webpack-dev-server: < 5.2.5 → fixed in 5.2.5

Impact When a user-configured proxy on `webpack-dev-server` has a broad context (e.g. `/`) and `ws: true`, it also intercepts the dev server's own HMR WebSocket and forwards it to the proxy target. This leaks the browser's cookies and `Origin` header to the backend, bypasses the dev server's Host/Origin validation, and corrupts the HMR socket (both HMR and the proxy end up writing to the same socket). Patches Fixed in `webpack-dev-server` 5.2.5. Workarounds Scope user-defined proxy `context` to specific paths instead of `/`, or omit `ws: true` from the proxy entry when WebSocket forwarding is not required.