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 was patched in v5.3.1, but the initial patch did not cover all problems. This has been fully patched in v5.3.2. A workaround involves not specifying individual content types in the schema.
https://hackerone.com/reports/3087928
https://github.com/fastify/fastify/security/advisories/GHSA-mg2h-6x62-wpwc
https://github.com/fastify/fastify/commit/f3d2bcb3963cd570a582e5d39aab01a9ae692fe4
https://github.com/fastify/fastify/commit/436da4c06dfbbb8c24adee3a64de0c51e4f47418