
Samsung Galaxy J5
The latest firmware for Samsung Galaxy J5 (SM-J500N0) is J500N0KOU1ARK1 with Android 5.1.1 (Lollipop), released on November 14, 2018 for 1 region (CSC). Every official firmware build for SM-J500N0, 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/J500N0KOU1ARK1
All 12 builds in our database run Android 5.1.1 (Lollipop). The newest build, J500N0KOU1ARK1, was released on November 14, 2018. No new build has appeared for 96 months, so regular updates for this model have most likely ended.
Specifications of SM-J500, a regional variant of the same device. Chipset and SIM lines are left out: they can differ by region.

SM-J500Y

SM-J510UN

SM-J600N

SM-J400M

SM-J700T1
The newest firmware for SM-J500N0 runs Android 5.1.1 (Lollipop): build J500N0KOU1ARK1, released on November 14, 2018.
The latest build for SM-J500N0, J500N0KOU1ARK1, was released on November 14, 2018 (7 years ago).
SM-J500N0 has had no new firmware for 96 months, so regular updates have most likely ended.
Yes, all firmware files for SM-J500N0 are 100% official, original, and obtained directly from Samsung servers.
To flash SM-J500N0, 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-J500N0.