Latest Samsung Galaxy S6 (SM-G920A) - ATT firmware
Samsung Galaxy S6 (SM-G920A) firmware for USA (AT&T) (ATT): 1 build in the SamMobile archive, newest first. The latest is G920AUCU7EVG1 (Android 7.0, built 27 July 2022). Open a build to download it, or switch region with the country selector.