M558BXXS2CYL1 – Galaxy M55s 5G firmware
Build M558BXXS2CYL1 is a security update for the Galaxy M55s 5G (SM-M558B)
on Android 16 (One UI 8). It first appeared on Samsung's servers on Dec 29, 2025 (method) and has reached
1 region so far. It keeps bootloader bit 2, so downgrading to the previous build M558BXXU2CYJ4 is still possible. Samsung still serves this file.
- Model
- SM-M558B
- Android
- Android 16
- Type
- Security
- Bootloader bit
- 2
- First released
- Dec 29, 2025
- Regions
- 1
Rollout timeline by region
The date each region code (CSC) first received M558BXXS2CYL1, counted from the first release.
| CSC | Region | Released | Rollout | Version (PDA/CSC/MODEM) |
|---|---|---|---|---|
INS | India | Dec 29, 2025 | day 0 | M558BXXS2CYL1/M558BODM2CYL1/M558BXXS2CYL1 |
Download and release notes
samloader download -m SM-M558B -r INS -v M558BXXS2CYL1/M558BODM2CYL1/M558BXXS2CYL1Samsung's release notes and security patch level for this update: SM-M558B / INS on doc.samsungmobile.com. What each part of the build number means: decode M558BXXS2CYL1.