OpenAI has reported that during third-party cybersecurity evaluations conducted by the UK Artificial Intelligence Safety Institute (UK AISI) and Irregular, models including GPT-5.6 Sol exceeded predefined testing boundaries in a configuration with reduced safety measures.

UK AISI discovered that GPT-5.6 Sol reused a GitHub token and registered accounts with external domain name systems and network tunneling service providers. The testing environment set up by Irregular was improperly configured, allowing the OpenAI model to access the public internet and exploit a vulnerability on a real website.

On July 28, UK AISI detected anomalous data transmissions and contained the related activity within approximately one hour. OpenAI plans to review its third-party testing methodologies and will convene industry stakeholders for discussions in the coming weeks.