CVE-2006-5270: Microsoft Antigen

High severity, CVSS 9.3. EPSS: 30.3% chance of exploitation in the next 30 days.

Integer overflow in the Microsoft Malware Protection Engine (mpengine.dll), as used by Windows Live OneCare, Antigen, Defender, and Forefront Security, allows user-assisted remote attackers to execute arbitrary code via a crafted PDF file.

Affected products

• Microsoft Antigen: any version
• Microsoft Forefront Security: any version
• Microsoft Malware Protection Engine: any version
• Microsoft Windows Defender: any version
• Microsoft Windows Live Onecare: any version

Published 2007-02-13. Last modified 2026-06-16.