CVE-2026-21248: Windows Hyper-V Remote Code Execution Vulnerability

Overview

Severity

High (CVSS 7.3)

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Category

Remote Code Execution

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2026-Feb

Released

2026-02-10

EPSS Score

0.03% (percentile: 7.7%)

Description

Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally.

FAQ

According to the CVSS metric, user interaction is required (UI:R) and privileges required is Low (PR:L). What does that mean for this vulnerability? The file must be stored in a location that allows an attacker write access, enabling the file to be corrupted. An attacker must send a user a crafted file and convince them to load it. According to the CVSS metric, the attack vector is local (AV:L). Why does the CVE title indicate that this is a remote code execution? The word Remote in the title refers to the location of the attacker. This type of exploit is sometimes referred to as Arbitrary Code Execution (ACE). The attack itself is carried out locally. This means an attacker or victim needs to execute code from the local machine to exploit the vulnerability.

Affected Products (21)

Windows

• Windows 10 Version 1809 for x64-based Systems
• Windows Server 2019
• Windows Server 2019 (Server Core installation)
• Windows Server 2022
• Windows Server 2022 (Server Core installation)
• Windows 10 Version 21H2 for x64-based Systems
• Windows Server 2025 (Server Core installation)
• Windows 11 Version 25H2 for ARM64-based Systems
• Windows 11 Version 25H2 for x64-based Systems
• Windows 11 Version 23H2 for ARM64-based Systems
• Windows 11 Version 23H2 for x64-based Systems
• Windows Server 2022, 23H2 Edition (Server Core installation)
• Windows 11 Version 24H2 for ARM64-based Systems
• Windows 11 Version 24H2 for x64-based Systems
• Windows Server 2025
• Windows 10 Version 1607 for x64-based Systems
• Windows Server 2016
• Windows Server 2016 (Server Core installation)
• Windows 11 Version 26H1 for ARM64-based Systems
• Windows 11 version 26H1 for x64-based Systems

ESU

• Windows 10 Version 22H2 for x64-based Systems

Security Updates (12)

• 5075904
• 5075906
• 5075943
• 5075912
• 5075899
• 5075942
• 5077181
• 5077212
• 5075941
• 5075897
• 5075999
• 5077179

Acknowledgments

cyanbamboo and b2ahex

Revision History

• 2026-02-10: Information published.