
Samsung Galaxy CORE
The latest firmware for Samsung Galaxy CORE (GT-I8260L) is I8260LUBANA1 with Android 4.1.2 (Jelly Bean), released on June 5, 2014 for 1 region (CSC). Every official firmware build for GT-I8260L, 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/I8260LUBANA1
All 8 builds in our database run Android 4.1.2 (Jelly Bean). The newest build, I8260LUBANA1, was released on June 5, 2014. No new build has appeared for 150 months, so regular updates for this model have most likely ended.

GT-I9308

GT-I9268

GT-I9228

GT-I9210

GT-I9108

GT-I9103

GT-I9100T

GT-I9050
The newest firmware for GT-I8260L runs Android 4.1.2 (Jelly Bean): build I8260LUBANA1, released on June 5, 2014.
The latest build for GT-I8260L, I8260LUBANA1, was released on June 5, 2014 (12 years ago).
GT-I8260L has had no new firmware for 150 months, so regular updates have most likely ended.
Yes, all firmware files for GT-I8260L are 100% official, original, and obtained directly from Samsung servers.
To flash GT-I8260L, 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 GT-I8260L.