ns2jb is a software-only, tethered jailbreak for the Nintendo Switch 2 that works on the current latest firmware, 23.0.1. The exploit lets users run arbitrary native code as an ordinary sysmodule or as the built-in fs sysmodule. This enables homebrew, reverse engineering and modding of Switch 2 games, backing up save files, and access to most of the console's peripherals through MMIO. The author says it is the first such exploit for the Switch 2.
To demonstrate the jailbreak's capabilities, an AI coding tool called Codex modded Mario Kart World, a Switch 2 exclusive, adding characters such as Cinnamoroll, Red, and Tole Tole. The author notes the game was vibecoded in a single day for fun, while the jailbreak itself took about two weeks of substantial effort. The setup used Jet KVMs to send controller inputs over USB and receive HDMI video output, plus a Bluetooth light switch to press the power button when the console crashes.
The initial code execution targeted WebKit, a popular console jailbreak target, through a Wi-Fi captive portal and an n-day vulnerability. The author explains that reaching sysmodules is harder, because WebKit's execute-only memory, Pointer Authentication (PAC) and control-flow integrity (CFI) complicate finding usable gadgets and calling them. As a side path, the author explored Switch 1 games that embed a browser, and the smilehax technique used against the 3DS, since the Switch 1 does not support PAC.
Source: Hacker News · Summarized by HeadlinesBriefing