The API in Atlassian Jira Server and Data Center before version 8.6.0 allows remote attackers to determine if a Jira project key exists or not via an information disclosure vulnerability.
The JMX monitoring flag in Atlassian Jira Server and Data Center before version 8.6.0 allows remote attackers to turn the JMX monitoring flag off or on via a Cross-site request forgery (CSRF) vulnerability.