EchoLeak
A zero-click vulnerability in Microsoft 365 Copilot in which an attacker injects hidden instructions through a specially crafted email, causing Copilot to leak sensitive data. It is a form of indirect prompt injection attack.
Timeline (last 90 days)
EchoLeak is a zero-click email injection attack in which the attacker sends an email containing instructions, and Copilot executes the instructions while summarizing the inbox and exfiltrates data through Markdown image links.
In June 2025, AIM Security disclosed the EchoLeak vulnerability in Microsoft 365 Copilot: an email carrying hidden instructions could make Copilot send sensitive data to an attacker without any user click.
Microsoft subsequently fixed the EchoLeak vulnerability on its side, and public reports state that the vulnerability was not found to have been exploited in real attacks.
EchoLeak (CVE-2025-32711, CVSS 9.3) is the first publicly documented case of prompt injection stealing data with zero user interaction, affecting Microsoft 365 Copilot.
All Facts (4)
Microsoft subsequently fixed the EchoLeak vulnerability on its side, and public reports state that the vulnerability was not found to have been exploited in real attacks.
50%UnverifiedEchoLeak is a zero-click email injection attack in which the attacker sends an email containing instructions, and Copilot executes the instructions while summarizing the inbox and exfiltrates data through Markdown image links.
50%UnverifiedIn June 2025, AIM Security disclosed the EchoLeak vulnerability in Microsoft 365 Copilot: an email carrying hidden instructions could make Copilot send sensitive data to an attacker without any user click.
50%UnverifiedEchoLeak (CVE-2025-32711, CVSS 9.3) is the first publicly documented case of prompt injection stealing data with zero user interaction, affecting Microsoft 365 Copilot.
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