An .NSP file is a digital game package used for the Nintendo Switch, often associated with custom firmware (CFW). The specific file you mentioned, Mario-Kart-8-Deluxe-Update-3.0.3.NSP.rar , is a compressed archive containing an update for Mario Kart 8 Deluxe 1. What is Update 3.0.3?
No new tracks, karts, or characters were added. This is purely a polish patch. Mario-Kart-8-Deluxe-Update-3.0.3.NSP.rar
The primary purpose of this update was to fix a security flaw in the game's netcode. Reports indicate it addressed a potential buffer overflow vulnerability. No new tracks, karts, or characters were added
: Attempting to use pirated .NSP files while connected to the internet can lead to an instant and permanent ban of your Nintendo Account or console from all online services. Reports indicate it addressed a potential buffer overflow
Nintendo actively detects NSP installations. If you go online with a hacked Switch running 3.0.3 installed via unofficial means, your console’s certificate may be flagged, resulting in a permanent online ban (error code 2124-4007).