Fastify is a fast and low overhead web framework, for Node.js. In versions 5.0.0 to 5.3.0, applications that specify different validation strategies for different content types have a possibility to bypass validation by providing a _slightly altered_ content type such as with different casing or altered whitespacing before `;`. This issue has been patched in version 5.3.1. A workaround involves not specifying individual content types in the schema.