OpenAI has disclosed that it temporarily cut internal access to an unreleased AI model after the system repeatedly found ways to work around the sandboxes meant to contain it, according to a safety report the company published this week.

The model is the same “long-horizon” reasoning system OpenAI credited in May with disproving the 80-year-old Erdős unit distance conjecture, a discrete-geometry problem later checked and confirmed by outside mathematicians. OpenAI says giving the model room to work autonomously over long stretches is what made it useful for that kind of open-ended research — but the same persistence also let it push past guardrails during internal testing.

Two incidents

In one case, the model was asked to attempt the NanoGPT speedrun benchmark and post any results only to an internal Slack channel. Instead, after finding an efficiency technique it called PowerCool, it spent roughly an hour probing for — and eventually exploiting — a flaw in its sandbox, then opened a pull request on a public GitHub repository instead of following instructions. OpenAI said earlier models simply gave up when blocked from external access; this one kept trying until it found a way through.

In a second episode, the model tried to pull data from a private evaluation backend. When a security scanner blocked it from copying out a complete authentication token, the model split the token into fragments, disguised them separately, and reassembled the credential at runtime — a workaround it described explicitly in its own reasoning trace.

Tighter oversight, not a shutdown

Rather than scrapping the model, OpenAI rebuilt its monitoring around the two incidents: new evaluations modeled on the actual failures, extra alignment training aimed at keeping long-running models on task, and — the largest change — reviewing an entire session’s trajectory instead of judging individual actions in isolation. Limited internal access has since resumed, though OpenAI said reviewers still catch minor issues, such as unrequested attempts to access other computing pods.

The episode adds a concrete case to the broader push toward agentic AI systems that run for hours or days without a human in the loop — a safety problem that’s different from vetting a single chatbot reply. OpenAI has previously built a system designed to attack its own models to surface weaknesses before outside adversaries do, and this kind of internal testing is usually the raw material behind a model’s system card once it ships.