Main Vulnerability Database Vulnerabilities #VU141951

Integer underflow in Microsoft Office for macOS and Microsoft Office - CVE-2026-64909

Published: August 12, 2026

Vulnerability identifier: #VU141951

CSH Severity: High

CVSS v4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-64909

CWE-ID: CWE-191

Exploitation vector: Remote access

Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to integer underflow in Microsoft Office when parsing a crafted Office file. A remote attacker can send a specially crafted file to execute arbitrary code.

User interaction is required to open the crafted file, and the Preview Pane can be used as an attack vector.

Affected software

Microsoft Office for macOS
Microsoft Office

How to mitigate CVE-2026-64909

Install security update from vendor's website.

Microsoft Office for macOS - update to 16.112.26081010
Microsoft Office - update to 16.0.5565.1001

External References

Related Security Bulletins