Use-after-free in Microsoft products - CVE-2026-40359
Published: May 13, 2026
Vulnerability identifier: #VU131338
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-2026-40359
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 system.
Affected software
Office Online Server
Microsoft 365 Apps for Enterprise
Microsoft Excel
Microsoft Office
Microsoft Office LTSC
Microsoft 365 Apps for Enterprise
Microsoft Excel
Microsoft Office
Microsoft Office LTSC
How to mitigate CVE-2026-40359
Install updates from vendor's website.