S918USQS8FZF5 – Galaxy S23 Ultra firmware

Build S918USQS8FZF5 is a security update for the Galaxy S23 Ultra (SM-S918U) on Android 16 (One UI 8). It first appeared on Samsung's servers on Jun 28, 2026 (method) and has reached 9 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 S918USQS7FZE3 is blocked. Samsung still serves this file.

Model
SM-S918U
Android
Android 16
Type
Security
Bootloader bit
8
First released
Jun 28, 2026
Regions
9

Rollout timeline by region

The date each region code (CSC) first received S918USQS8FZF5, counted from the first release.

CSCRegionReleasedRolloutVersion (PDA/CSC/MODEM)
ATTUSA (AT&T)Jun 28, 2026day 0S918USQS8FZF5/S918UOYN8FZF5/S918USQS8FZF5
CCTUSA (Comcast)Jun 28, 2026day 0S918USQS8FZF5/S918UOYN8FZF5/S918USQS8FZF5
TMBUSA (T-Mobile)Jun 28, 2026day 0S918USQS8FZF5/S918UOYN8FZF5/S918USQS8FZF5
TMKUSA (MetroPCS)Jun 28, 2026day 0S918USQS8FZF5/S918UOYN8FZF5/S918USQS8FZF5
DSAUSAJun 30, 2026+2 daysS918USQS8FZF5/S918UOYN8FZF5/S918USQS8FZF5
DSHUSAJun 30, 2026+2 daysS918USQS8FZF5/S918UOYN8FZF5/S918USQS8FZF5
VZWUSA (Verizon)Jun 30, 2026+2 daysS918USQS8FZF5/S918UOYN8FZF5/S918USQS8FZF5
XAAUSA (unlocked)Jun 30, 2026+2 daysS918USQS8FZF5/S918UOYN8FZF5/S918USQS8FZF5
USCUSA (US Cellular)Jul 1, 2026+3 daysS918USQS8FZF5/S918UOYN8FZF5/S918USQS8FZF5

Download and release notes

samloader download -m SM-S918U -r XAA -v S918USQS8FZF5/S918UOYN8FZF5/S918USQS8FZF5

Samsung's release notes and security patch level for this update: SM-S918U / XAA on doc.samsungmobile.com. What each part of the build number means: decode S918USQS8FZF5.