Samsung SM-X306N firmware for Korea (KOO): 2 builds in the SamMobile archive, newest first. The latest is X306NKOS9CZA3 (Android 16, built 15 January 2026). Open a build to download it, or switch region with the country selector.
We recommend using Samsung’s own utilities, Samsung Smart Switch and OTA (Over-the-air), to upgrade devices. Use SamMobile only if you are 100% sure about the risks involved in flashing
your device. SamMobile is not responsible for any damage caused by using the files on this website.
