A security researcher has demonstrated a software-only partial jailbreak of the Switch 2, gaining “userland” access that he says “lets us run homebrew, reverse engineer and mod Switch 2 games, back up save files off the Switch, and access most of the Switch 2’s peripherals through MMIO.”

The hack relies on the original Switch version of SmileBasic 4 , the latest in a long-running series of programming environments and interpreters that run on Nintendo hardware. The so-called “tethered” hack also requires access to a macOS or Linux PC on the same network to run a node.js package that helps enable privileged system access.

Researcher Sammy Hajhamid writes that he used OpenAI’s Codex to poke at SmileBasic’s language interpreter, using a custom harness that could send USB commands to the system and view results via HDMI (as well as power cycling via a Bluetooth light switch flipping device).…