Elasticsearch versions from 6.7.0 before 6.8.8 and 7.0.0 before 7.6.2 contain a privilege escalation flaw if an attacker is able to create API keys. An attacker who is able to generate an API key can perform a series of steps that result in an API key being generated with elevated privileges.
Elasticsearch versions 7.0.0-7.3.2 and 6.7.0-6.8.3 contain a username disclosure flaw was found in the API Key service. An unauthenticated attacker could send a specially crafted request and determine if a username exists in the Elasticsearch native realm.