In all Kubernetes versions prior to v1.11.8, v1.12.6, and v1.13.4, users that are authorized to make patch requests to the Kubernetes API Server can send a specially crafted patch of type "json-patch" (e.g. `kubectl patch --type json` or `"Content-Type: application/json-patch+json"`) that consumes excessive resources while processing, causing a Denial of Service on the API Server.
https://security.netapp.com/advisory/ntap-20190416-0002/
https://groups.google.com/forum/#%21topic/kubernetes-announce/vmUUNkYfG9g
https://github.com/kubernetes/kubernetes/issues/74534
https://access.redhat.com/errata/RHSA-2019:3239