--- title: Cerulean Agent Release Notes - 2304.3.5 description: AgileBlue originally released the Cerulean Agent (2304 series) on August 3, 2023. The current version is 2304.3.3 --- [Skip to content](https://help.agileblue.com/cerulean-agent#main-content) English Show submenu for translations [Contact AgileBlue Support](https://help.agileblue.com/kb-tickets/new?hsLang=en) [Customer portal](https://help.agileblue.com/support-ticket-status?hsLang=en) ![FullColor-800px-Aug-04-2025-07-56-16-5066-PM.png\]](https://help.agileblue.com/hs-fs/hubfs/FullColor-800px-Aug-04-2025-07-56-16-5066-PM.png?height=32&name=FullColor-800px-Aug-04-2025-07-56-16-5066-PM.png) Open main navigation Close main navigation - English Show submenu for translations - [Contact AgileBlue Support](https://help.agileblue.com/kb-tickets/new) - [Customer portal](https://help.agileblue.com/support-ticket-status) - AgileBlue Portal AgileBlue Portal Hello. How can we help you? - There are no suggestions because the search field is empty. 1. [Help Center](https://help.agileblue.com/?hsLang=en) 2. [Release Notes](https://help.agileblue.com/release-notes?hsLang=en) # Cerulean Agent Release Notes - 2304.3.5 ## AgileBlue originally released the Cerulean Agent (2304 series) on August 3, 2023. The current version is 2304.3.5. ### Overview This release focuses on a significant reliability overhaul of the agent's core service supervisor, several data-integrity fixes, and platform/version updates. **Update, September 24, 2026:** Cerulean Agent 2304.3.5 is now in full release and available to all customers. To update your agents, refer to [this guide](https://help.agileblue.com/update-your-agileblue-cerulean-agent-version?hsLang=en). --- ### New Features **Agent Version Command** The agent CLI now supports a version subcommand, allowing administrators to quickly confirm the installed agent version from the command line without inspecting the installer package or logs. --- ### Reliability & Stability Improvements This release includes a ground-up rewrite of the agent's internal service supervisor – the component responsible for keeping each agent subsystem (Elastic, Response, Nodeware, Redis messaging) running and automatically restarting it if it stops responding. The goals were fewer unnecessary restarts, faster and cleaner shutdowns, and no lost work during a restart. - **Smarter hang detection**: each subsystem now reports a real, in-progress heartbeat instead of a heartbeat that could keep ticking even if the subsystem was actually stuck. Detection thresholds are now tuned per subsystem (up to 30 minutes for install/download-heavy work), which eliminates false-positive restarts during legitimately long-running operations. - **Safer restarts**: a subsystem that is restarted no longer risks corrupting shared state or leaving duplicate work running — each restart is fully isolated from the one before it. - **Faster, more reliable shutdown**: the agent service now shuts down cleanly and predictably, including in cases that previously could hang indefinitely and require a forced kill of the service. - **No leaked connections**: fixed an issue where repeated restarts of a subsystem could each leave behind an open network connection, gradually consuming resources over time. - **Automated test coverage**: added an extensive automated test suite for the supervisor and related subsystems to guard against regressions in this critical part of the agent going forward. --- ### Bug Fixes - **Fixed: failed SOC actions could be reported as succeeded.** A messaging bug meant that when a response action failed, the agent could still record it in the portal as successful. This is corrected so the portal now accurately reflects the true outcome of every action. - **Fixed: potential crash/restart loop on some Windows hosts.** A missing error-handling step meant that if the underlying Windows Filtering Platform network session failed to initialize, the agent could crash and restart repeatedly. The agent now handles this failure gracefully. - **Fixed: agent could lose its enrollment identity on an unexpected crash.** Agent and policy identifiers were previously only saved to disk in a way that could be lost if the agent stopped unexpectedly, occasionally forcing a device to re-enroll. State is now saved safely to disk on every update, preventing this loss. - **Fixed: unnecessary policy lookups.** The agent previously re-checked for its Elastic policy ID more often than necessary. It now reuses the existing policy ID once found, reducing unnecessary network calls. - **Improved: fleet status is refreshed live before each device check-in**, so the status reported to the management console is always current rather than following a fixed 30-minute cycle. --- ### Compatibility & Platform Updates - Bundled Elastic Agent updated from 8.18.5 to 8.19.9, bringing in the latest upstream detection and fleet-management improvements. - Elastic Agent client initialization was refactored for more consistent error handling and configuration setup across platforms. - Enhanced support for Mac OS 26.x and newer --- *Questions? 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