CVE-2019-16788

In WordPress versions from 3.7 to 5.3.0, authenticated users who do not have the rights to publish a post are able to mark posts as sticky or unsticky via the REST API. For example, the contributor role does not have such rights, but this allowed them to bypass that. This has been patched in WordPress 5.3.1, along with all the previous WordPress versions from 3.7 to 5.3 via a minor release. Automatic updates are enabled by default for minor releases and we strongly recommend that you keep them enabled.

Source: CVE-2019-16788