What the ChatGPT for Sheets data-exfiltration bug teaches about AI security

A security firm called PromptArmor published a writeup on May 27, 2026 showing that ChatGPT for Google Sheets, an OpenAI extension with than 185,000 downloads, could be made to steal a user's spreadsheets through a single ordinary-looking request. Four days later, on May 31, OpenAI shipped a fix. The short version is that one benign question, typed by a real user into a sheet that contained hidden instructions, was enough to drain twelve linked workbooks out of that user's account and replace the assistant with a fake phishing chatbot.