The DNS Trap: How a “Hidden” Path Allowed ChatGPT to Silently Leak Your Private Data

Check Point Research discovered a DNS tunneling side channel in ChatGPT's Linux-based code execution environment that allowed sensitive user data to be encoded into DNS queries and exfiltrated to an attacker-controlled server, and could also enable a remote shell into the runtime. The company demonstrated the issue via a proof-of-concept (a “personal doctor” GPT) that leaked PDF patient data; OpenAI patched the underlying issue on February 20, 2026.