A566U1UES9CZG7 – Galaxy A56 5G firmware

Build A566U1UES9CZG7 is a security update for the Galaxy A56 5G (SM-A566U1) on Android 16 (One UI 8). It first appeared on Samsung's servers on Jul 26, 2026 (method) and has reached 11 regions so far. It raises the bootloader bit from 8 to 9: once installed, the device no longer accepts firmware with bit 8 or lower, so a downgrade to A566U1UES8CZF6 is blocked. Samsung still serves this file.

Model
SM-A566U1
Android
Android 16
Type
Security
Bootloader bit
9
First released
Jul 26, 2026
Regions
11

Rollout timeline by region

The date each region code (CSC) first received A566U1UES9CZG7, counted from the first release.

CSCRegionReleasedRolloutVersion (PDA/CSC/MODEM)
ACGUSA (C Spire)Jul 26, 2026day 0A566U1UES9CZG7/A566U1OYM9CZG7/A566U1UES9CZG7
AIOUSA (Cricket)Jul 26, 2026day 0A566U1UES9CZG7/A566U1OYM9CZG7/A566U1UES9CZG7
ATTUSA (AT&T)Jul 26, 2026day 0A566U1UES9CZG7/A566U1OYM9CZG7/A566U1UES9CZG7
CCTUSA (Comcast)Jul 26, 2026day 0A566U1UES9CZG7/A566U1OYM9CZG7/A566U1UES9CZG7
LRAUSA (Bluegrass)Jul 26, 2026day 0A566U1UES9CZG7/A566U1OYM9CZG7/A566U1UES9CZG7
TMBUSA (T-Mobile)Jul 26, 2026day 0A566U1UES9CZG7/A566U1OYM9CZG7/A566U1UES9CZG7
TMKUSA (MetroPCS)Jul 26, 2026day 0A566U1UES9CZG7/A566U1OYM9CZG7/A566U1UES9CZG7
USCUSA (US Cellular)Jul 26, 2026day 0A566U1UES9CZG7/A566U1OYM9CZG7/A566U1UES9CZG7
VZWUSA (Verizon)Jul 26, 2026day 0A566U1UES9CZG7/A566U1OYM9CZG7/A566U1UES9CZG7
XAAUSA (unlocked)Jul 26, 2026day 0A566U1UES9CZG7/A566U1OYM9CZG7/A566U1UES9CZG7
XARUSA (Cellular South)Jul 26, 2026day 0A566U1UES9CZG7/A566U1OYM9CZG7/A566U1UES9CZG7

Download and release notes

samloader download -m SM-A566U1 -r XAA -v A566U1UES9CZG7/A566U1OYM9CZG7/A566U1UES9CZG7

Samsung's release notes and security patch level for this update: SM-A566U1 / XAA on doc.samsungmobile.com. What each part of the build number means: decode A566U1UES9CZG7.