CVE-2021-28456: Microsoft 365 Apps

Medium severity, CVSS 5.5. EPSS: 3.7% chance of exploitation in the next 30 days.

Microsoft Excel Information Disclosure Vulnerability

Affected products

• Microsoft 365 Apps: affected versions not specified
• Microsoft Excel: version 2010 only; version 2013 only; version 2016 only
• Microsoft Office: version 2019 only
• Microsoft Office Online Server: affected versions not specified
• Microsoft Office Web Apps Server: version 2013 only

Published 2021-04-13. Last modified 2026-06-17.