External Control of File Name or Path in Microsoft products - CVE-2026-40421
Published: May 13, 2026
Vulnerability identifier: #VU131354
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-40421
CWE-ID: CWE-73
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Microsoft
Affected software:
Microsoft 365 Apps for Enterprise
Microsoft Office
Microsoft Word
Microsoft Office LTSC
Microsoft 365 Apps for Enterprise
Microsoft Office
Microsoft Word
Microsoft Office LTSC
Detailed vulnerability description
The vulnerability allows a remote attacker to compromise the target system.
The vulnerability exists due to external control of file name or path in Microsoft Word. A remote attacker can trick a victim to open a specially crafted Office file and gain access to sensitive information on the system.
How to mitigate CVE-2026-40421
Install updates from vendor's website.