In Kibana versions before 7.12.0 and 6.8.15 a flaw in the session timeout was discovered where the xpack.security.session.idleTimeout setting is not being respected. This was caused by background polling activities unintentionally extending authenticated users sessions, preventing a user session from timing out.
Kibana versions before 6.8.9 and 7.7.0 contains a stored XSS flaw in the TSVB visualization. An attacker who is able to edit or create a TSVB visualization could allow the attacker to obtain sensitive information from, or perform destructive actions, on behalf of Kibana users who edit the TSVB visualization.