Irregular, an Israeli start-up, worked with OpenAI, Anthropic and Meta to assess the security of their A.I. models. It made a mistake. Then the tests went off the rails.

Hugging Face, a start-up that was breached by rogue bots from OpenAI, is using the hack to push for openness in A.I. development.

The offering could value the five-year-old A.I. start-up at $2 trillion, its bankers have told potential investors, which would exceed Elon Musk’s SpaceX.