Link following in Microsoft Windows and Windows Server - CVE-2025-21391

Vulnerability identifier: #VU103777

CSH Severity: Medium

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2025-21391

CWE-ID: CWE-59

Exploitation vector: Local access

Exploit availability: The vulnerability is being exploited in the wild

The vulnerability allows a local user to delete files on the system.

The vulnerability exists due to insecure link following in Windows Storage. A local user can delete arbitrary files on the system.

Note, the vulnerability is being actively exploited in the wild.

Microsoft Windows
Windows Server

Install updates from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.5487, 10 22H2 10.0.19045.5487, 10 1507 10.0.10240.20915, 10 1607 10.0.14393.7785, 10 1809 10.0.17763.6893, 11 22H2 10.0.22621.4890, 11 23H2 10.0.22631.4890, 11 24H2 10.0.26100.3107
Windows Server - addressed in versions 2016 10.0.14393.7785, 2022 23H2 10.0.25398.1425, 2022 10.0.20348.3148, 2022 10.0.20348.3207, 2025 10.0.26100.3107, 2025 10.0.26100.3194

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21391

• Arbitrary file deletion in Windows Storage