CVE-2024-21413: Microsoft Outlook Improper Input Validation Vulnerability

Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2025-02-06. EPSS: 94.7% chance of exploitation in the next 30 days.

Microsoft Outlook Remote Code Execution Vulnerability

Affected products

• Microsoft 365 Apps: affected versions not specified
• Microsoft Office 2016: affected versions not specified
• Microsoft Office 2019: affected versions not specified
• Microsoft Office Long Term Servicing Channel: version 2021 only

Published 2024-02-13. Last modified 2026-08-10.