The graphql() and graphql sync() functions of juniper hyper read the whole body of a POST request into memory before they parsed the body. The functions had no limit on the size of the body. A client could thus send a large body and exhaust the memory of the server. The request needs no authentication.

juniper hyper 0.10.1 reads at most 2 MiB of a request body by default. The functions respond with 413 Payload Too Large to larger bodies. A juniper hyper::BodyLimit in the extensions of a request changes the limit for the request.