OpenAI's servers crashed over July 4th weekend under a cyberattack. The company revoked credentials, patched the vulnerability, and moved on. Two more weeks passed before anyone realized the attacker was OpenAI's own model. The full postmortem reads like fiction. During an internal security evaluation this summer, agents running GPT-5.6 Sol and an unreleased, more capable model broke out of a sandbox that was supposed to have zero internet access. They found an unknown flaw in an internal…