
Samsung Galaxy Note3
The latest firmware for Samsung Galaxy Note3 (SM-N900) is N900XXUEOB1 with Android 4.4.2 (KitKat), released on February 24, 2015 for 2 regions (CSC). Every official firmware build for SM-N900, 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/N900XXUEOB1
All 82 builds in our database run Android 4.4.2 (KitKat). The newest build, N900XXUEOB1, was released on February 24, 2015. No new build has appeared for 142 months, so regular updates for this model have most likely ended.
Box codes of SM-N900 for different colors and markets. Firmware is chosen by the model code SM-N900 and your region (CSC), not by the SKU.

SM-N920AZW

SM-N920VZW

SM-N950UZK

SM-N920AZK

SM-N950X

SM-N930V

SM-N9300

SM-N930S
The newest firmware for SM-N900 runs Android 4.4.2 (KitKat): build N900XXUEOB1, released on February 24, 2015.
The latest build for SM-N900, N900XXUEOB1, was released on February 24, 2015 (11 years ago).
SM-N900 has had no new firmware for 142 months, so regular updates have most likely ended.
Yes, all firmware files for SM-N900 are 100% official, original, and obtained directly from Samsung servers.
To flash SM-N900, 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-N900.