Microsoft Outlook Improper Input Validation Vulnerability

Added to KEV
2025-02-06
Federal due date
2025-02-27
Vendor
Microsoft
Product
Office Outlook
EPSS
99.8th percentile (score 0.930, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Unknown
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2024-21413

CISA short description

Microsoft Outlook contains an improper input validation vulnerability that allows for remote code execution. Successful exploitation of this vulnerability would allow an attacker to bypass the Office Protected View and open in editing mode rather than protected mode.

Required action

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.