Nintendo Pulls SmileBASIC 4 as Tethered Switch 2 Jailbreak ns2jb Appears

A tethered, software-only Switch 2 jailbreak called ns2jb has surfaced, and Nintendo appears to have pulled SmileBASIC 4 from the eShop.

Nintendo appears to have removed SmileBASIC 4 from the eShop after a Switch 2 jailbreak surfaced, Nintendo Life reported.

Security researcher Sammy Hajhamid, who goes by pepsipu, built the exploit, called ns2jb, with help from OpenAI's Codex.

Hajhamid released it on October 22 and it targets Switch 2 firmware 23.0.1. Nintendo Life wrote that, apart from the delisting, Nintendo has not officially responded.

Readers following the wider Nintendo Switch scene should note that the exploit is far from a finished custom firmware.

What ns2jb Does and Does Not Do

The exploit lets arbitrary native code run on the console, without a hardware modchip.

Hajhamid says that opens the door to homebrew software, reverse engineering and modding Switch 2 games, and backing up save files.

Notebookcheck added that it is tethered, so it does not survive a reboot. Restarting the console clears the exploit from memory.

In practice, owners would have to rerun the procedure every time the console powers off. Notebookcheck noted that ns2jb offers no persistent custom firmware.

Mario Kart World Demo

To show what the jailbreak can do, Hajhamid modded the Switch 2 exclusive Mario Kart World. Nintendo Life listed Cinnamoroll, Peter Griffin and Hatsune Miku among the added characters.

Notebookcheck also named Red from Angry Birds.

How SmileBASIC 4 Became the Way In

The method relies on the original Switch version of SmileBASIC 4, a programming tool, running through Switch 2 backward compatibility.

Notebookcheck said the flaws Hajhamid found eventually gave native code execution with higher system permissions.

Coverage of the technical write-up describes the starting point as a 32-bit integer overflow, a counting error, in how the game handles arrays.

Hajhamid's own write-up (pepsipu.com) lists the requirements. Users need SmileBASIC 4.4.9, system software 23.0.1, and Node.js 22 or later on macOS or Linux.

They also need more than 20 MiB of free space in the SmileBASIC save.

A game that was needed to run the exploit is no longer on sale. Nintendo Life said the exploit depends on a certain version of the now-removed title.

Outside Verification and Precedent

Notebookcheck cited developer Gezine, who recently revealed a separate universal exploit affecting the original Switch and Switch 2. Gezine said he spoke with Hajhamid and that the work seems legit.

He also said Hajhamid knew of his userland exploit, which is a different one from ns2jb.

Hajhamid believes this is the first such exploit for the Switch 2. He said he is excited to see upcoming Switch 2 homebrew, emulation and modding.

Nintendo Life noted that SmileBASIC was also used for homebrew exploits on the 3DS.