Fluentd collects events from various data sources and writes them to files, RDBMS, NoSQL, IaaS, SaaS, Hadoop and so on. Prior to 1.19.3, Fluentd's Monitor Agent plugin in_monitor_agent exposes internal metrics and plugin information via a REST API, and responses from /api/plugins.json and related endpoints unintentionally include internal instance variables that may contain database passwords, API keys, or cloud credentials. This issue is fixed in version 1.19.3.
https://github.com/fluent/fluentd/security/advisories/GHSA-pr7j-96cj-549h
https://github.com/fluent/fluentd/releases/tag/v1.19.3
https://github.com/fluent/fluentd/pull/5392
https://github.com/fluent/fluentd/commit/990921518971699b9a97441970674d1800e29177