It was discovered that Kibana was not sanitizing document fields containing HTML snippets. Using this vulnerability, an attacker with the ability to write documents to an elasticsearch index could inject HTML. When the Discover app highlighted a search term containing the HTML, it would be rendered for the user.

Kibana versions before 7.12.1 contain a denial of service vulnerability was found in the webhook actions due to a lack of timeout or a limit on the request size. An attacker with permissions to create webhook actions could drain the Kibana host connection pool, making Kibana unavailable for all other users.