Elastic X-Pack Security versions 5.0.0 to 5.4.0 contain a privilege escalation bug in the runas functionality. This bug prevents transitioning into the specified user specified in a runas request. If a role has been created using a template that contains the user properties, the behavior of runas will be incorrect. Additionally if the runas user specified does not exist, the transition will not happen.

An error was found in the permission model used by X-Pack Alerting 5.0.0 to 5.6.0 whereby users mapped to certain built-in roles could create a watch that results in that user gaining elevated privileges.

X-Pack 5.1.1 did not properly apply document and field level security to multi-search and multi-get requests so users without access to a document and/or field may have been able to access this information.

Kibana versions prior to 5.6.1 had a cross-site scripting (XSS) vulnerability in Timelion that could allow an attacker to obtain sensitive information from or perform destructive actions on behalf of other Kibana users.

Kibana versions 5.1.1 to 6.1.2 and 5.6.6 had a cross-site scripting (XSS) vulnerability via the colored fields formatter that could allow an attacker to obtain sensitive information from or perform destructive actions on behalf of other Kibana users.