615 Series Protection Relays Firmware Update Release 4.0.7

This document details firmware update release 4.0.7 for ABB’s 615 series protection relays (REF615, REM615, RET615, REU615, RED615), including critical cyber security fixes for Ripple20 vulnerabilities (CVE-2020-11907 through CVE-2020-11912) and improvements to supervision, protection, and communication functions. It also lists enhancements from previous releases 4.0.6 and 4.0.5, covering control, HMI, and synchrocheck behavior.