CVE-2026-40420 HIGH

CVE-2026-40420: Microsoft Office Click-To-Run Elevation of Privilege Vulnerability

Vendor Microsoft
Product Microsoft 365 Apps for Enterprise
Weakness CWE-284
Published May 12, 2026
Last update June 9, 2026
View on NVD All CVEs

CVSS base score

8.8/10
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C

What the vulnerability does

01Description

Use after free in Microsoft Office allows an authorized attacker to elevate privileges locally.

Key dates

02Disclosure timeline

May 12, 2026 CVE published
June 9, 2026 Record updated