Use-after-free in Microsoft products - CVE-2026-26107
Published: March 11, 2026
Vulnerability identifier: #VU123802
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-2026-26107
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in Microsoft Excel. A remote attacker can trick a victim to open a specially crafted Office file and execute arbitrary code on the target system.
Affected software
Microsoft 365 Apps for Enterprise
Microsoft Office
Microsoft Excel
Microsoft Office LTSC
Office Online Server
Microsoft Office
Microsoft Excel
Microsoft Office LTSC
Office Online Server
How to mitigate CVE-2026-26107
Install updates from vendor's website.
Microsoft Excel - update to 16.0.5543.1000
Office Online Server - update to 16.0.10417.20102
Office Online Server - update to 16.0.10417.20102