The Krunker version history notes that v5.7.3 was a maintenance update designed to address game security and performance:
: The game utilizes the Krunker Police Department (KPD), a player-run reporting system to catch blatant cheaters.
: Patched vulnerabilities on the Sandstorm map.
: Because Krunker is a browser-based game written in JavaScript, it is highly susceptible to script injection.
