OpenAI models go rogue during testing, trigger 'unprecedented' breach at startup Hugging Face
- Last updated: July 23, 2026 | 14:46
ChatGPT maker OpenAI says it is still investigating the "unprecedented cyber incident” that led its artificial intelligence systems to break out of a testing environment and hack into another AI company.
OpenAI said on Tuesday two of its most capable AI models were responsible for the cyberattack targeting AI startup Hugging Face. The incident is stirring debates over the need for stronger AI guardrails and the extent to which AI agents are capable of acting on their own.
Hugging Face said last week that it had detected an intrusion into its data processing systems that it suspected was caused by an AI agent autonomously acting on its own. But the New York-based startup said it wasn't until this week that it learned OpenAI was responsible, and it worked with the larger company to contain what Hugging Face CEO Clément Delangue called "an attack unlike anything we’ve seen before.”
San Francisco-based OpenAI said its AI used stolen credentials and discovered a previously unknown vulnerability to access Hugging Face's servers. It was working with reduced guardrails because it was supposed to be in an isolated testing environment known as a sandbox.
But it went to "extreme lengths to achieve a rather narrow testing goal,” finding ways to connect to the internet without human direction and "gain access to secret information that it could use to cheat the evaluation,” the company said.
University of Amsterdam social scientist Hannes Cools said the framing of the cyberattack as an AI agent acting on its own is an unnecessary anthropomorphisation that takes some of the heat off the company.
"It is a human decision to switch off specific safeguards," said Cools. "It’s not an AI that goes rogue in that sense. It followed specific instructions based on the prompt that was given to that AI system.”
'AI models cause problems without human direction'
Even so, other experts say the cleverness with which the AI models were able to cause problems without human direction speaks to the dangers. OpenAI said the intrusion was caused by a combination of its AI models, including its newly released GPT‑5.6 Sol and an "even more capable” model that is still being tested internally.
"It went off and did this hack all by itself, as far as we can tell,” said Colin Shea-Blymyer, a cybersecurity research fellow at Georgetown University’s Center for Security and Emerging Technology. "This is the highest level of autonomy that we’ve seen in the use of a large language model for cyber operations."
One of the most surprising innovations in what Shea-Blymyer describes as an "almost entirely self-directed” attack was the AI agent's apparently independent decision to target Hugging Face, a well-known AI development hub and marketplace.
He said OpenAI's internal environment for testing AI capabilities and risks worked a "little bit like putting a student in a room and telling them, ‘Do bad things. Your job now is to evaluate how bad of a person you can be.’ And then you lock the room and you leave for the weekend and you come back and they’ve left the room.”
But then "the cybersecurity agent that was being tested broke out of its sandbox, had access to the internet and sort of thought to itself, ‘Who would have the answers to the test that I’m working on?’”
The answer was Hugging Face, a repository for AI testing data.
"And so the agent thought, ‘Well, we’ll go to the teacher’s house,’ so to speak. And from there it devised a plan to break in and steal the answer key,” he said.
The hack comes at a time of intense debate about the benefits and risks of open-source AI models, particularly those built in China that are cheaper and almost as good as those that US-based "frontier AI” companies like Anthropic, Google and OpenAI are building.
OpenAI's models are not open
Despite its name, OpenAI's models are closed. Hugging Face, by contrast, is a big promoter of open-source technology, in which developers make key components accessible for anyone to examine, modify and build upon.
Hugging Face co-founder and chief science officer Thomas Wolf said the attack has reinforced his belief in the importance of wide access to open-source models for cybersecurity defence. Hugging Face used a Chinese model to combat the intrusion.
"When a frontier model is attacking you and moving laterally inside your infrastructure, defenders need wide access to near-frontier tools within hours or even minutes, rather than being pointed towards a closed-door” platform, Wolf wrote in a social media post.
Associated Press