
Samsung Galaxy Note3
The latest firmware for Samsung Galaxy Note3 (SM-N900L) is N900LKLUFNK1 with Android 4.4.2, released on November 2, 2014 for 1 region (CSC). Every official firmware build for SM-N900L, 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/N900LKLUFNK1
All 2 builds in our database run Android 4.4.2. The newest build, N900LKLUFNK1, was released on November 2, 2014. No new build has appeared for 145 months, so regular updates for this model have most likely ended.
Specifications of SM-N900, a regional variant of the same device. Chipset and SIM lines are left out: they can differ by region.

SM-N900V

SM-N910V

SM-N915V

SM-N916S

SM-N920AZW
The newest firmware for SM-N900L runs Android 4.4.2: build N900LKLUFNK1, released on November 2, 2014.
The latest build for SM-N900L, N900LKLUFNK1, was released on November 2, 2014 (11 years ago).
SM-N900L has had no new firmware for 145 months, so regular updates have most likely ended.
Yes, all firmware files for SM-N900L are 100% official, original, and obtained directly from Samsung servers.
To flash SM-N900L, 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-N900L.