Severity
Exposure
Date of incident
ChatGPT Plugin Data Exfil
reported
Tier -
B
Plugin OAuth scopes exfiltrated data — CASB logged SaaS login not tool/call.
What Happened
Researcher chained browsing and API plugins; demonstrated PII leaving session via plugin tool calls — OAuth scopes invisible to enterprise CASB.
Sumarry
Security research demonstrated ChatGPT plugin tool chains exfiltrating data via over-scoped OAuth and chained plugin calls.
Detect
Tool OAuth scope audit
What Happened
Per-tool egress policy at MCP hop
Blekline //
Tool allow-list + mask at MCP hop
Without agent boundary //
Manual plugin store review — no runtime OAuth scope reduction
