Severity
Exposure
Date of incident
Microsoft Copilot EchoLeak
confirmed
Tier -
A
Zero-click injection exfiltrated Copilot session — no tool egress boundary.
What Happened
Attacker sent crafted email with hidden instructions; M365 Copilot processed context and exfiltrated sensitive session data via zero-click indirect prompt injection — Microsoft patched CVE-2025-32711 server-side.
Sumarry
Aim Security disclosed EchoLeak — zero-click indirect prompt injection in Microsoft 365 Copilot (CVE-2025-32711); Microsoft patched server-side.
Detect
Lineage contamination + exfil tool deny after untrusted ingest
What Happened
Agent boundary on Copilot tool egress
Blekline //
Lineage block + tool policy on Copilot connectors
Without agent boundary //
Await vendor patch — no customer-controlled execution hop
