On October 18, 2026, security researcher Sammy Hajhamid, who publishes as Pepsipu, disclosed ns2jb, a software-only, tethered jailbreak for Nintendo Switch 2. Hajhamid reported compatibility with firmware 23.0.1 and access to system modules, short of kernel-level control.
What ns2jb reportedly enables
Hajhamid says ns2jb can run native code with ordinary system-module permissions and the permissions of the built-in fs module. That is userland access: code runs outside the console’s kernel, the core that manages the operating system and hardware.
He says this access enables homebrew, game modifications, save-file backups and reverse engineering. It can also reach most peripherals through memory-mapped I/O (MMIO), a way for software to interact with hardware through mapped memory addresses. The reported access does not extend to kernel control.
“Tethered” means the exploit must be activated again after a full reboot. Hajhamid describes the jailbreak as software-only and tethered, so it is not a permanent custom firmware installation.
How the reported exploit chain works
Hajhamid describes two vulnerabilities in sequence. The first is a 32-bit integer overflow in how the original Nintendo Switch version of SmileBASIC 4 handles array removal. He says that flaw provided memory read and write capabilities. The second is a buffer overflow in path normalization inside the Switch 2’s built-in fs module, which he says enabled arbitrary read and write access within that module.
Together, the flaws enabled the reported native-code execution with system-module and fs permissions. The chain’s access level remains below the kernel.
What the Mario Kart World proof of concept showed
Hajhamid reported modifying Mario Kart World with custom characters. His example shows a game modification made with ns2jb, rather than a general-purpose modding platform.
Codex assisted research that took about two weeks
Hajhamid said OpenAI Codex helped identify the SmileBASIC overflow and contributed to his research. He put the jailbreak work at about two weeks; the Mario Kart World modification took one day.
