Sophos Firewall v21.5 and later versions no longer support legacy XG and SG Series hardware appliances . If you are using these older models, you should stick to the latest compatible v20 MR release. How to Download Sophos XG Firmware
Then, a single green light blinked on the XG’s front panel. Then another. The fans roared back to life. A POST message scrolled on the console port: “Loading SFOS 19.5.3…” sophos xg latest firmware version download
Released in April 2026, is the latest maintenance release following the major v22 GA launch in December 2025. Release Date: April 20, 2026. Sophos Firewall v21