EchoLeak — zero-click Microsoft Copilot data exfiltration via email prompt injection
Date: 2026-01-15
Affected: Microsoft Copilot for M365 — enterprise email and file data
Attack vector: prompt-injection
Category: research-demonstrated
Severity: Critical
CVE: CVE-2025-32711
CWE: CWE-74
CVSS:  (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N)

Critical zero-click exploit (CVE-2025-32711) allowing a mere email to trigger Microsoft Copilot leaking confidential data — emails, files, chat logs — outside intended scope. No user interaction required.

Impact: Zero-click data exfiltration; enterprise data breach; no user awareness

Mitigations:
Anomaly detection for bulk data access patterns
Data loss prevention for AI-generated outputs
Email content sanitization before AI processing

Architectural layers (MAESTRO):
label: Agent Frameworks
notes: Copilot processes email content containing hidden prompt injection
role: origin
label: Data Operations
notes: Emails, files, and chat logs exfiltrated
role: impact