#VU122556 External Control of File Name or Path in Windows and Windows Server - CVE-2026-21249
Published: February 10, 2026 / Updated: February 19, 2026
Vulnerability identifier: #VU122556
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:L/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-2026-21249
CWE-ID: CWE-73
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Windows
Windows Server
Windows
Windows Server
Software vendor:
Microsoft
Microsoft
Description
The vulnerability allows a remote attacker to read arbitrary files.
The vulnerability exists due to External Control of File Name or Path in Windows NTLM. A remote attacker can trick a victim to open a specially crafted Office file and read arbitrary files on the system.
Remediation
Install updates from vendor's website.