It would be interesting to read the post mortem (if they will release). In particular in which phase of the training it escaped the sandbox, in which way it used the information. Training is different from inference, I doubt there is a context there and where would the model store these information? In the weights?! That makes little sense to me
Simon Willison’s blog has some useful insights into what might have happened here: https://simonwillison.net/2026/Jul/22/openai-cyberattack/
Ok this would be at inference time (solving the challenges) as opposed to the training that was described in the article.
This makes things more believable