An issue was identified by Elastic whereby sensitive information is recorded in Logstash logs under specific circumstances.

The prerequisites for the manifestation of this issue are:

Logstash is configured to log in JSON format https://www.elastic.co/guide/en/logstash/current/running-logstash-command-line.html , which is not the default logging format.

Sensitive data is stored in the Logstash keystore and referenced as a variable in Logstash configuration.