
Samsung Galaxy A5
The latest firmware for Samsung Galaxy A5 (SM-A500FU) is A500FUXXU1CSB1 with Android 5.0.2 (Lollipop), released on April 5, 2019 for 32 regions (CSC). Every official firmware build for SM-A500FU, 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/A500FUXXU1CSB1
SM-A500FU started on Android 4 and has received 1 major Android upgrade; it now runs Android 5.0.2 (Lollipop). The newest build, A500FUXXU1CSB1, was released on April 5, 2019. No new build has appeared for 92 months, so regular updates for this model have most likely ended.
Box codes of SM-A500FU for different colors and markets. Firmware is chosen by the model code SM-A500FU and your region (CSC), not by the SKU.

SM-A500X

SM-A507FN

SM-A505YN

SM-A600A

SM-A515X
The newest firmware for SM-A500FU runs Android 5.0.2 (Lollipop): build A500FUXXU1CSB1, released on April 5, 2019.
The latest build for SM-A500FU, A500FUXXU1CSB1, was released on April 5, 2019 (7 years ago).
SM-A500FU has had no new firmware for 92 months, so regular updates have most likely ended.
Yes, all firmware files for SM-A500FU are 100% official, original, and obtained directly from Samsung servers.
To flash SM-A500FU, 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-A500FU.