Astro is a web framework for content-driven websites. Prior to 11.1.3, the @astrojs/node adapter builds a request URL from the Host header, and a malformed port can make that URL invalid. The recovery path reuses the same malformed host and throws an uncaught TypeError: Invalid URL before routing begins. In the default standalone configuration, the request returns an HTTP 500 response and the server continues running, but when staticHeaders is enabled the synchronous handler does not catch the exception and the Node process terminates. Proxies and CDNs that reject malformed Host headers prevent this path from reaching the origin. The issue affects availability only and does not expose data or permit code execution. This issue is fixed in version 11.1.3.