ChatGPT for Google Sheets exfiltrates workbooks

ChatGPT for Google Sheets Extension Found Exfiltrating User Data

TL;DR

• Critical vulnerability: A popular ChatGPT integration for Google Sheets has been discovered transmitting entire workbooks to external servers without explicit user consent
• Widespread exposure: The extension's user base remains unclear, but the discovery highlights risks in third-party AI tool integrations with sensitive data platforms
• Immediate action needed: Users should audit recent spreadsheet activity and consider revoking extension permissions until the issue is resolved

What happened

Security researchers have identified a data exfiltration vulnerability in a ChatGPT extension designed for Google Sheets, according to findings published on Prompt Armor. The extension, which promises to integrate OpenAI's language model capabilities directly into spreadsheets, was found transmitting complete workbook contents to remote servers—a practice users likely never authorized.

The discovery underscores a critical risk in the burgeoning ecosystem of AI-powered productivity tools. While Google Sheets integrations have become increasingly popular for automating tasks like data analysis, content generation, and formula creation, many users may not fully understand what data these extensions access or where it flows.

The vulnerability appears to stem from overly permissive API requests and insufficient transparency around data handling practices. When users install browser extensions or add-ons that interact with Google Workspace, they typically grant broad permissions to read and modify spreadsheet contents—permissions that malicious or poorly-designed code can easily abuse.

This incident has generated significant discussion in the developer community, with 47 comments on Hacker News examining the technical details, responsible disclosure practices, and broader implications for AI tool security.

What happens next

Users of ChatGPT-integrated Google Sheets extensions should immediately review their installed add-ons and remove any extensions they don't actively use. Check Google Account activity logs for suspicious third-party application access. If you've used such extensions with sensitive financial, healthcare, or proprietary business data, consider rotating credentials and reviewing file sharing settings.

For a deeper technical analysis, visit the original report on Prompt Armor's resources page. This article does not contain affiliate links.