CVE-2026-21248

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-21248
Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally.

7.3 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 1.3 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21248 Vendor Advisory
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*
History

11 Feb 2026, 20:15

Type Values Removed Values Added
CPE cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*
CWE CWE-787
References () https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21248 - () https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21248 - Vendor Advisory
First Time Microsoft windows 10 22h2
Microsoft windows 10 21h2
Microsoft windows 10 1607
Microsoft windows 11 23h2
Microsoft windows 11 24h2
Microsoft windows Server 2019
Microsoft windows 10 1809
Microsoft windows Server 2022 23h2
Microsoft windows 11 25h2
Microsoft windows Server 2025
Microsoft windows Server 2022
Microsoft windows Server 2016
Microsoft

10 Feb 2026, 18:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-02-10 18:16

Updated : 2026-02-11 20:15

NVD link : CVE-2026-21248

Mitre link : CVE-2026-21248

CVE.ORG link : CVE-2026-21248

JSON object : View

Products Affected

microsoft

  • windows_server_2019
  • windows_10_1809
  • windows_11_24h2
  • windows_11_25h2
  • windows_11_23h2
  • windows_server_2016
  • windows_server_2022
  • windows_server_2022_23h2
  • windows_server_2025
  • windows_10_22h2
  • windows_10_21h2
  • windows_10_1607
CWE
CWE-122

Heap-based Buffer Overflow

CWE-787

Out-of-bounds Write