HTTP request body disclosure in github.com/go-resty/resty/v2

A race condition in go-resty can result in HTTP request body disclosure across requests. This condition can be triggered by calling sync.Pool.Put with the same *bytes.Buffer more than once, when request retries are enabled and a retry occurs. The call to sync.Pool.Get will then return a bytes.Buffer that hasn't had bytes.Buffer.Reset called on it. This dirty buffer will contain the HTTP request body from an unrelated request, and go-resty will append the current HTTP request body to it, sending two bodies in one request. The sync.Pool in question is defined at package level scope, so a completely unrelated server could receive the request body.