A security researcher has demonstrated a software-only partial jailbreak of Nintendo's Switch 2, gaining what he calls "userland" access that allows homebrew software, game modding, save-file backups and access to most of the console's hardware peripherals — though not yet full control of the system.
The exploit, developed by a researcher known as Pepsipu, relies on SmileBasic 4, an old Nintendo-sanctioned programming environment also available on the original Switch. Using OpenAI's Codex to probe the software's language interpreter, Pepsipu found a 32-bit integer overflow after what he described as "substantial effort for ~2 weeks" of testing — a flaw that exposed an array pointer giving read-and-write access to portions of system memory. From there, he found a second flaw, a buffer overflow in the console's file system module, that ultimately allowed native code execution.
As proof of concept, Pepsipu showed off new modded characters running in Mario Kart World, and other hackers in the community have since demonstrated early homebrew tools of their own. The hack is "tethered," requiring a connected macOS or Linux computer to enable, and works only on SmileBasic 4, which Nintendo has already delisted worldwide from the Switch 2 eShop — a move that could slow, but likely not stop, the exploit's spread.
The SmileBasic name has history: the same software was central to 2016's "smilehax" exploit on the Nintendo 3DS, which Nintendo also moved quickly to delist. Unlike the original Switch's unpatchable 2018 hardware exploit, which required Nintendo to redesign future consoles entirely, this flaw is expected to be patched out in a coming firmware update — setting up what is likely to be a running cycle of hacks and patches for the console going forward.