
Samsung Galaxy Ace
The latest firmware for Samsung Galaxy Ace (SM-G357M) is G357MUBU0AOG2 with Android 4.4.2 (KitKat), released on July 8, 2015 for 9 regions (CSC). Every official firmware build for SM-G357M, newest first: one row per build with all regions (CSC) that received it.
Each firmware build has its own page at https://samfirm.shop/build/{PDA}, where {PDA} is the build number from the list above. Example: https://samfirm.shop/build/G357MUBU0AOG2
All 16 builds in our database run Android 4.4.2 (KitKat). The newest build, G357MUBU0AOG2, was released on July 8, 2015. No new build has appeared for 137 months, so regular updates for this model have most likely ended.
Box codes of SM-G357M for different colors and markets. Firmware is chosen by the model code SM-G357M and your region (CSC), not by the SKU.

SM-G935TZK

SM-G930AZK

SM-G935AZS

SM-G935TZS

SM-G935AZK

SM-G935TZD

SM-G975WC

SM-G975FC
The newest firmware for SM-G357M runs Android 4.4.2 (KitKat): build G357MUBU0AOG2, released on July 8, 2015.
The latest build for SM-G357M, G357MUBU0AOG2, was released on July 8, 2015 (11 years ago).
SM-G357M has had no new firmware for 137 months, so regular updates have most likely ended.
Yes, all firmware files for SM-G357M are 100% official, original, and obtained directly from Samsung servers.
To flash SM-G357M, you need to download the appropriate firmware, put your device into Download Mode, and use the Odin tool to load the BL, AP, CP, and CSC files.
Downgrading is only possible if the bootloader version (binary bit) of the old firmware matches the current one. Always check the binary version before flashing SM-G357M.