M556BXXS5CZB4 – Galaxy M55 5G firmware

Build M556BXXS5CZB4 is a security update for the Galaxy M55 5G (SM-M556B) on Android 16 (One UI 8). It first appeared on Samsung's servers on Mar 3, 2026 (method) and has reached 13 regions so far. It raises the bootloader bit from 4 to 5: once installed, the device no longer accepts firmware with bit 4 or lower, so a downgrade to M556BXXS4CYL1 is blocked. Samsung still serves this file.

Model
SM-M556B
Android
Android 16
Type
Security
Bootloader bit
5
First released
Mar 3, 2026
Regions
13

Rollout timeline by region

The date each region code (CSC) first received M556BXXS5CZB4, counted from the first release.

CSCRegionReleasedRolloutVersion (PDA/CSC/MODEM)
BNGBelgiumMar 3, 2026day 0M556BXXS5CZB4/M556BODM5CZB4/M556BXXS5CZB4
INSIndiaMar 3, 2026day 0M556BXXS5CZB4/M556BODM5CZB4/M556BXXS5CZB4
NPBNepalMar 3, 2026day 0M556BXXS5CZB4/M556BODM5CZB4/M556BXXS5CZB4
SLKSri LankaMar 3, 2026day 0M556BXXS5CZB4/M556BODM5CZB4/M556BXXS5CZB4
EGYEgyptMar 8, 2026+5 daysM556BXXS5CZB4/M556BOJM5CZB4/M556BXXS5CZB4
ILOIsraelMar 8, 2026+5 daysM556BXXS5CZB4/M556BOJM5CZB4/M556BXXS5CZB4
MIDMiddle EastMar 8, 2026+5 daysM556BXXS5CZB4/M556BOJM5CZB4/M556BXXS5CZB4
XXVVietnamMar 8, 2026+5 daysM556BXXS5CZB4/M556BOLM5CZB4/M556BXXS5CZB4
CHOChileMar 9, 2026+6 daysM556BXXS5CZB4/M556BOWO5CZB1/M556BXXS5CZB4
COOColombiaMar 9, 2026+6 daysM556BXXS5CZB4/M556BOWO5CZB1/M556BXXS5CZB4
PEOPeruMar 9, 2026+6 daysM556BXXS5CZB4/M556BOWO5CZB1/M556BXXS5CZB4
TPAPanamaMar 9, 2026+6 daysM556BXXS5CZB4/M556BOWO5CZB1/M556BXXS5CZB4
ZTOBrazilMar 9, 2026+6 daysM556BXXS5CZB4/M556BOWO5CZB1/M556BXXS5CZB4

Download and release notes

samloader download -m SM-M556B -r INS -v M556BXXS5CZB4/M556BODM5CZB4/M556BXXS5CZB4

Samsung's release notes and security patch level for this update: SM-M556B / INS on doc.samsungmobile.com. What each part of the build number means: decode M556BXXS5CZB4.