CVE-2026-40366 HIGH

CVE-2026-40366: Microsoft Word Remote Code Execution Vulnerability

Vendor Microsoft
Product Microsoft 365 Apps for Enterprise
Weakness CWE-416
Published May 12, 2026
Last update June 9, 2026
View on NVD All CVEs

CVSS base score

8.4/10
Attack vector Local
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

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

What the vulnerability does

01Description

Access of resource using incompatible type ('type confusion') in Microsoft Office Word allows an unauthorized attacker to execute code locally.

Key dates

02Disclosure timeline

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