# Researcher finds ChatGPT ad code sends a shared identifier across websites

_Published Sunday, September 20, 2026 at 2:08 PM EDT · Products, Security · Latest · Tier 2 — Notable_

A researcher found that OpenAI's advertising code can send the same browser identifier back to OpenAI when a person visits different advertisers' websites. In tests on Chrome for Android, the identifier appeared in requests from 12 commercial sites.

The researcher said ChatGPT creates a token linking the identifier to an account or anonymous device. OpenAI accepted the subsequent website requests, but the researcher could not observe whether it linked those browsing events to an account internally.

OpenAI Support acknowledged the inquiry without answering questions about why the identifier is classified as an analytics cookie. Desktop Chrome was not tested, and the researcher said iOS browser protections block the mechanism.

## Sources

- [buchodi.com](https://www.buchodi.com/chatgpt-now-knows-what-you-do-on-other-websites-via-ad-collector/)

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Canonical: https://techandbusiness.org/newswire/MK22unYuon15lKZ-3Nnylo
Published: 2026-09-20T18:08:08.622Z
Story chronology: 2026-09-20T15:18:44.000Z
Retrieved: 2026-11-04T23:02:10.110Z
Publisher: Tech & Business (techandbusiness.org)