In 95% of cases, the answer is . The Sagemcom FAST 5364 is designed to be a "managed device." It connects to a TR-069 management server operated by your ISP. When the ISP tests a new firmware version and approves it for mass rollout, they push it to the router automatically.
As of early 2026, standard firmware versions typically follow an prefix. Notable versions include: SG4K100136 : Identified as a recent stable release. SG4K10002816t sagemcom fast 5364 firmware