ACTIVELY EXPLOITED

CVE-2023-23397: Microsoft Office Outlook Privilege Escalation Vulnerability

Facts
VendorMicrosoft
ProductOffice
Actively exploitedYes
Added to CISA KEV14 Mar 2023
CISA federal deadline4 Apr 2023
Weakness (CWE)CWE-294

Required action (CISA's text)

Apply updates per vendor instructions.

Description (NVD)

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

SOURCES

Other Microsoft flaws

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.