Heap-based buffer overflow in Microsoft Windows and Windows Server - CVE-2025-49721

Vulnerability identifier: #VU112508

CSH Severity: High

CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2025-49721

CWE-ID: CWE-122

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error in Windows Fast FAT File System Driver. A remote attacker can trick a victim into mounting a specially crafted VHD, trigger a heap-based buffer overflow and execute arbitrary code on the target system with elevated privileges.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Microsoft Windows
Windows Server

Install update from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.6093, 10 22H2 10.0.19045.6093, 10 1507 10.0.10240.21073, 10 1607 10.0.14393.8246, 10 1809 10.0.17763.7558, 11 22H2 10.0.22621.5624, 11 23H2 10.0.22631.5624, 11 24H2 10.0.26100.4652
Windows Server - addressed in versions 2008 R2 6.1.7601.27820, 2008 6.0.6003.23418, 2012 R2 6.3.9600.22676, 2012 6.2.9200.25573, 2016 10.0.14393.8246, 2019 10.0.17763.7558, 2022 23H2 10.0.25398.1732, 2022 10.0.20348.3932, 2025 10.0.26100.4652, 2025 10.0.26200.4349

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-49721

• Heap-based buffer overflow in Microsoft Windows Fast FAT File System Driver