Double free in Microsoft products - CVE-2026-118296
Published: November 11, 2026
Vulnerability identifier: #VU165091
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-2026-118296
CWE-ID: CWE-415
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 double free in Microsoft Office Excel when processing a specially crafted file. A remote attacker can trick a user into opening the crafted file to execute arbitrary code.
The Preview Pane is not an attack vector for this vulnerability.
Affected software
Microsoft Office for macOS
Microsoft Office
Office Online Server
Microsoft Office
Office Online Server
How to mitigate CVE-2026-118296
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