Heap-based buffer overflow in Microsoft products - CVE-2026-40363
Published: May 13, 2026
Vulnerability identifier: #VU131321
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-40363
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Microsoft
Affected software:
Microsoft 365 Apps for Enterprise
Microsoft Office
Microsoft Office LTSC
Microsoft Office for Android
Microsoft 365 Apps for Enterprise
Microsoft Office
Microsoft Office LTSC
Microsoft Office for Android
Detailed vulnerability description
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error in Microsoft Office. A remote attacker can pass specially crafted data to the application, trigger a heap-based buffer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
How to mitigate CVE-2026-40363
Install updates from vendor's website.