Use-after-free in Microsoft products - CVE-2026-118703
Published: November 11, 2026
Vulnerability identifier: #VU165105
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-2026-118703
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 with the victim user's privileges.
The vulnerability exists due to use-after-free in Microsoft Office Excel when handling objects in a specially crafted workbook. A remote attacker can convince a user to open the workbook, cut and paste an object in it, and then close the application to execute arbitrary code with the user's privileges.
The Preview Pane is not an attack vector.
Affected software
Microsoft Office for macOS
Microsoft Office
Office Online Server
Microsoft Office
Office Online Server
How to mitigate CVE-2026-118703
Install security update from vendor's website.
Microsoft Office for macOS - update to 16.115.26110837
Office Online Server - update to 16.0.10417.20236
Microsoft Office - addressed in versions 16.0.14334.21048, 16.0.17932.21140
Office Online Server - update to 16.0.10417.20236
Microsoft Office - addressed in versions 16.0.14334.21048, 16.0.17932.21140