Main Vulnerability Database Vulnerabilities #VU164751

Heap-based buffer overflow in Microsoft Office for macOS and Microsoft Office - CVE-2026-109500

Published: November 10, 2026

Vulnerability identifier: #VU164751

CSH Severity: Medium

CVSS v4: 7.1 [CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-109500

CWE-ID: CWE-122

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 a heap-based buffer overflow in Microsoft Office Word when processing a specially crafted document that causes unusually large memory operations. A remote attacker can trick a victim into opening such a document to execute arbitrary code.

Exploitation depends on memory conditions that the attacker cannot fully control.

Affected software

Microsoft Office for macOS
Microsoft Office

How to mitigate CVE-2026-109500

Install security update from vendor's website.

Microsoft Office for macOS - update to 16.115.26110837
Microsoft Office - addressed in versions 16.0.14334.21048, 16.0.17932.21140

External References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-109500

Related Security Bulletins