During January 2026, Guillaume Fontaine focused on enhancing the security and reliability of the centreon/centreon-plugins repository by upgrading critical dependencies. He updated log4j from version 2.17.1 to 2.25.3, addressing known vulnerabilities and improving logging capabilities, and also upgraded undertow-core from 2.3.17.Final to 2.3.22.Final to incorporate bug fixes and performance enhancements. Working primarily with Java, XML, and build tools, Guillaume ensured that these changes were traceable through well-documented commits. His work reduced security risks and improved runtime stability, providing a smoother upgrade path for downstream users and strengthening the maintainability of the Centreon plugins ecosystem.