Nintendo Switch 2 has been partially jailbroken, and Mario Kart World already has some bizarre new racers

Mario Kart World already has an extensive selection of racers. Apparently, that was not enough for security researcher Sammy Hajhamid.

His latest demonstration features unexpected characters from animation, games and popular culture racing on a modified Nintendo Switch 2.

The footage is the visible result of a more substantial technical experiment: ns2jb, a software-only jailbreak designed to execute unofficial code on Nintendo's current console.

Hajhamid's technical write-up is dated October 18, 2026. The demonstration attracted wider attention on October 22, when technology and gaming publications began reporting the achievement.

The word jailbreak sounds definitive, but this is a partial and experimental breakthrough rather than a simple method for permanently unlocking every Switch 2.

Mario Kart World demonstrates the possibilities

Hajhamid used Mario Kart World to illustrate what his exploit could accomplish.

His published images and videos show a Switch 2 running modified game content, including characters such as Cinnamoroll, Peter Griffin, Hatsune Miku and the red Angry Bird.

The demonstration establishes that selected content in a Switch 2-exclusive game can be modified using the researcher's techniques.

It does not establish that every Switch 2 game can already be modified in the same way.

Nor does it mean that all of the console's security protections have been removed.

The footage remains notable because the modified game is a native Switch 2 release rather than merely a program designed for the previous console.

The entry point comes from an older programming game

The research began with SmileBASIC 4, a programming environment originally released for the first Nintendo Switch.

The application allows users to write and run their own BASIC programs.

Because Switch 2 supports compatible software from the earlier console, Hajhamid investigated SmileBASIC as a possible point of entry.

He reports that Codex identified an integer-overflow vulnerability in the interpreter, enabling access to memory outside the expected boundaries.

Additional research then targeted parts of the console's internal software.

This does not mean that writing ordinary programs in SmileBASIC normally grants unrestricted access to the operating system.

The reported behavior results from vulnerabilities rather than a deliberately provided programming feature.

No modchip, but no permanent unlock

One of the exploit's distinguishing characteristics is that it requires no hardware modification inside the console.

However, it is tethered, meaning that it does not persist after a restart.

The relevant procedure must be performed again when the console is rebooted.

The developer and GBAtemp also distinguish ns2jb from full custom firmware or complete kernel-level control.

These restrictions make the demonstration substantially different from a consumer-friendly permanent jailbreak.

The required technical knowledge and complexity remain significant.

Codex helped, but the AI did not work alone

Hajhamid used OpenAI Codex as a research assistant, assigning agents tasks involving vulnerability discovery and experimentation.

He also constructed a hardware test environment allowing the agents to interact with consoles and observe their responses.

The researcher specifically clarified that the initial goal of automatically reaching userland code execution did not succeed.

He says the complete jailbreak effort required roughly two weeks of substantial human work.

The Mario Kart World modifications were created much more quickly, with Codex assistance, in approximately one day according to his account.

The achievement therefore demonstrates human-directed AI-assisted security research, not a fully autonomous system breaking into a console without preparation.

What could this mean for Switch 2 games?

The most immediate possibilities concern homebrew software and game modifications.

Hajhamid also describes capabilities involving technical analysis of the system and access to certain save data.

These are capabilities reported by the researcher, not proof that every player can reliably perform every operation on every console.

The method may provide a starting point for further security research and community experimentation.

However, its compatibility, reliability and future evolution remain uncertain.

Nintendo's next move is unknown

Hajhamid reports that his exploit works on firmware version 23.0.1, which he identifies as current at the time of his research.

Software vulnerabilities may be addressed through future updates, but no specific Nintendo response or confirmed patch was established by the principal sources reviewed for this report.

Predictions about the exploit being removed or permanently prevented should therefore remain speculative.

Players should also be aware that unauthorized system modifications can create stability, security and service-access risks.

A significant experiment rather than an unlocked console

The ns2jb demonstration is important because it combines software vulnerability research, AI assistance and actual changes to a Switch 2-exclusive game.

Its limitations are equally important.

The exploit is not permanent, does not provide complete system control and remains highly technical.

For the modding community, it may represent an important step toward a deeper understanding of the console.

For everyone else, the most immediate result is simply an extraordinary Mario Kart World demonstration that required far more work than installing a character pack.