A266U1UES8BZD4 – Galaxy A26 5G firmware

Build A266U1UES8BZD4 is a security update for the Galaxy A26 5G (SM-A266U1) on Android 16 (One UI 8). It first appeared on Samsung's servers on May 3, 2026 (method) and has reached 13 regions so far. It raises the bootloader bit from 7 to 8: once installed, the device no longer accepts firmware with bit 7 or lower, so a downgrade to A266U1UES7BZB6 is blocked. Samsung still serves this file.

Model
SM-A266U1
Android
Android 16
Type
Security
Bootloader bit
8
First released
May 3, 2026
Regions
13

Rollout timeline by region

The date each region code (CSC) first received A266U1UES8BZD4, counted from the first release.

CSCRegionReleasedRolloutVersion (PDA/CSC/MODEM)
ACGUSA (C Spire)May 3, 2026day 0A266U1UES8BZD4/A266U1OYM8BZD4/A266U1UES8BZD4
AIOUSA (Cricket)May 3, 2026day 0A266U1UES8BZD4/A266U1OYM8BZD4/A266U1UES8BZD4
ATTUSA (AT&T)May 3, 2026day 0A266U1UES8BZD4/A266U1OYM8BZD4/A266U1UES8BZD4
CCTUSA (Comcast)May 3, 2026day 0A266U1UES8BZD4/A266U1OYM8BZD4/A266U1UES8BZD4
DSAUSAMay 3, 2026day 0A266U1UES8BZD4/A266U1OYM8BZD4/A266U1UES8BZD4
DSHUSAMay 3, 2026day 0A266U1UES8BZD4/A266U1OYM8BZD4/A266U1UES8BZD4
LRAUSA (Bluegrass)May 3, 2026day 0A266U1UES8BZD4/A266U1OYM8BZD4/A266U1UES8BZD4
TMBUSA (T-Mobile)May 3, 2026day 0A266U1UES8BZD4/A266U1OYM8BZD4/A266U1UES8BZD4
TMKUSA (MetroPCS)May 3, 2026day 0A266U1UES8BZD4/A266U1OYM8BZD4/A266U1UES8BZD4
USCUSA (US Cellular)May 3, 2026day 0A266U1UES8BZD4/A266U1OYM8BZD4/A266U1UES8BZD4
VZWUSA (Verizon)May 3, 2026day 0A266U1UES8BZD4/A266U1OYM8BZD4/A266U1UES8BZD4
XAAUSA (unlocked)May 3, 2026day 0A266U1UES8BZD4/A266U1OYM8BZD4/A266U1UES8BZD4
XARUSA (Cellular South)May 3, 2026day 0A266U1UES8BZD4/A266U1OYM8BZD4/A266U1UES8BZD4

Download and release notes

samloader download -m SM-A266U1 -r XAA -v A266U1UES8BZD4/A266U1OYM8BZD4/A266U1UES8BZD4

Samsung's release notes and security patch level for this update: SM-A266U1 / XAA on doc.samsungmobile.com. What each part of the build number means: decode A266U1UES8BZD4.