
Samsung GALAXY S II
The latest firmware for Samsung GALAXY S II (SGH-T989) is T989WXME1 with Jelly(Android Bean), released on May 7, 2013 for 1 region (CSC). Every official firmware build for SGH-T989, 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/T989WXME1
The newest build, T989WXME1, was released on May 7, 2013. No new build has appeared for 163 months, so regular updates for this model have most likely ended.
Box codes of SGH-T989 for different colors and markets. Firmware is chosen by the model code SGH-T989 and your region (CSC), not by the SKU.

SGH-I927

SGH-S730M

SGH-T999N

SGH-T989D

SGH-T859

SGH-T599V

SGH-I757M

SGH-I747
The latest build for SGH-T989, T989WXME1, was released on May 7, 2013 (13 years ago).
SGH-T989 has had no new firmware for 163 months, so regular updates have most likely ended.
Yes, all firmware files for SGH-T989 are 100% official, original, and obtained directly from Samsung servers.
To flash SGH-T989, 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 SGH-T989.