Microsoft Office Outlook Privilege Escalation Vulnerability

Added to KEV
2023-03-14
Federal due date
2023-04-04
Vendor
Microsoft
Product
Office
EPSS
99.8th percentile (score 0.934, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Unknown
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2023-23397

CISA short description

Microsoft Office Outlook contains a privilege escalation vulnerability that allows for a NTLM Relay attack against another service to authenticate as the user.

Required action

Apply updates per vendor instructions.

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.