ChatGPT Targeted: “ShadowLeak” Zero-Click Vulnerability in Deep Research Could Exfiltrate Gmail Data A Complete Cyber Threat Analysis Report — By CyberDudeBivash Author: CyberDudeBivash · Powered by: CyberDudeBivash
Executive summary Researchers at Radware disclosed ShadowLeak , a zero-click indirect prompt-injection flaw in ChatGPT’s Deep Research agent that, when connected to Gmail (and browsing enabled), could exfiltrate inbox data via a single crafted email —with no user interaction and no visible UI cues . OpenAI confirmed and patched the issue before public disclosure (September 18–20, 2025). The attack is notable for being service-side : data leaves OpenAI’s cloud rather than the user’s device, making enterprise detection far harder. SecurityWeek +3 radware.com +3 radware.com +3 What is Deep Research and why it was exposed Deep Research lets users delegate multi-step tasks to an agentic AI that can browse and access connected data sources (e.g., Gmail, Google Drive) to compile findings. The agent will read emails/attachments as part of its task plan. This connective power, combined with prompt-following , makes it high-impact if an attacker can plant hidden instructions t...