CVE-2020-16949: Microsoft 365 Apps

Medium severity, CVSS 4.7. EPSS: 3% chance of exploitation in the next 30 days.

A denial of service vulnerability exists in Microsoft Outlook software when the software fails to properly handle objects in memory. An attacker who successfully exploited the vulnerability could cause a remote denial of service against a system. Exploitation of the vulnerability requires that a specially crafted email be sent to a vulnerable Outlook server. The security update addresses the vulnerability by correcting how Microsoft Outlook handles objects in memory.

Affected products

Microsoft 365 Apps: affected versions not specified
Microsoft Office: version 2019 only
Microsoft Outlook: version 2010 only; version 2013 only; version 2016 only
Microsoft Windows 10: affected versions not specified; version 1607 only; version 1709 only; version 1803 only; version 1809 only; version 1903 only; …
Microsoft Windows 7: affected versions not specified
Microsoft Windows 8.1: affected versions not specified
Microsoft Windows Rt 8.1: affected versions not specified
Microsoft Windows Server 2008: affected versions not specified; version r2 only
Microsoft Windows Server 2012: affected versions not specified; version r2 only
Microsoft Windows Server 2016: affected versions not specified; version 1903 only; version 1909 only; version 2004 only
Microsoft Windows Server 2019: affected versions not specified

Published 2020-10-16. Last modified 2026-06-17.