fastify is a fast and low overhead web framework, for Node.js. Affected versions of fastify are subject to a denial of service via malicious use of the Content-Type header. An attacker can send an invalid Content-Type header that can cause the application to crash. This issue has been addressed in commit `fbb07e8d` and will be included in release version 4.8.1. Users are advised to upgrade. Users unable to upgrade may manually filter out http content with malicious Content-Type headers.