Browser extensions harvested private AI chats into a commercial database
What happened
A researcher found private chatbot conversations captured by browser extensions, stored in a vector database and sold through an API. The data included healthcare workers pasting patient details and people asking about their immigration status.
Researcher Lee Dryburgh documented that data brokers sell access to AI chatbot conversations captured by browser extensions installed by people who agreed to join a browsing "panel", often without realising their chats were included. By querying one venture-backed platform, he retrieved hundreds of verbatim prompts from more than 400 panelists across about 20 sensitive categories, stored in a searchable vector database. They included medical diagnoses and lab results, clinical notes with real patient details written by healthcare workers, questions about immigration status, legal matters and domestic violence. The findings built on earlier research by Koi Security, which in December 2025 showed Urban VPN and related extensions with more than 8 million users had been quietly collecting full conversations from ChatGPT, Claude, Gemini, Copilot and other assistants since mid-2025, and passing browsing data to an affiliated analytics firm.
How it happened
Supply chain and access: Third-party leak. Data leaked through a vendor or tool connected to the AI service rather than the AI service itself.
Models from several AI vendors were involved. The product was Browser extensions, a type of chatbot.
Impact
Data was exposed. Data involved: chat logs, personal data and health. Many organizations were affected.
Severity is rated High, calculated from how far the incident reached and how sensitive the data was.
Was the AI at fault?
No. The failure was in the systems, settings or people around the AI, not in the model's behaviour.
Status and timeline
Reported in the press or by researchers, but not confirmed by the affected organization, the AI vendor or a regulator.
It became public on 3 Mar 2026.
Security researchers advised users to uninstall the extensions involved, since the collection ran in the background whether or not the extension's main feature was switched on.