
Samsung SM-W2018
The latest firmware for Samsung SM-W2018 (SM-W2018X) is W2018XZCU1ARA3, released on March 18, 2018 for 1 region (CSC). Every official firmware build for SM-W2018X, 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/W2018XZCU1ARA3

SM-W9025

SM-W7025

SM-W7024

SM-W9024

SM-W7023

SM-W9023

SM-W2022

SM-W2021
You can find the firmware on the model: SM-W2018X page.
Yes, all firmware files for SM-W2018X are 100% official, original, and obtained directly from Samsung servers.
To flash SM-W2018X, 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-W2018X.