CVE-2023-23397
KEVMicrosoft Office Outlook Privilege Escalation Vulnerability
Description
Microsoft Office Outlook contains a privilege escalation vulnerability that allows for a NTLM Relay attack against another service to authenticate as the user.
Microsoft Outlook Elevation of Privilege Vulnerability
CVSS 3.1 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HPublishedMar 14, 2023
Last modifiedJun 17, 2026
Added to KEVMar 14, 2023
Remediation dueApr 4, 2023
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2023-23397PatchVendor Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-23397US Government Resource
0 recent articles mention this CVE
89
Risk assessment · Critical
Actively exploited. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 1302 days
- CVSS
- 9.8 CRITICAL
- EPSS (30-day exploit probability)
- 97.2% · top 1% of all CVEs
- Weakness
- CWE-20
- Attack vector
- Network, remotely reachable
- Preconditions
- No privileges and no user interaction
Recommended actions
- 1.Apply updates per vendor instructions.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
- 4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.