Use-after-free in Microsoft Office for macOS and Microsoft Office - CVE-2026-109491
Published: November 10, 2026
Vulnerability identifier: #VU164743
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-2026-109491
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code on the affected system.
The vulnerability exists due to use-after-free in Microsoft Office Word when processing attacker-controlled content. A remote attacker can supply specially crafted content that, when processed with user interaction, triggers access to freed memory to execute arbitrary code.
The Preview Pane is not an exploitation vector for this vulnerability.
Affected software
Microsoft Office for macOS
Microsoft Office
Microsoft Office
How to mitigate CVE-2026-109491
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
Microsoft Office - addressed in versions 16.0.14334.21048, 16.0.17932.21140