CVE-2026-21248
Windows Hyper-V Remote Code Execution Vulnerability
Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Windows Hyper-V Remote Code Execution Vulnerability
Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally.
- Record
CVE-2026-21248- CVSS 3.1
- 7.3 High
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 - Weakness
- CWE-122
- Updated
- 2026-11-02
EUVDEUVD-2026-7357
Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally.
- Record
EUVD-2026-7357- CVSS 3.1
- 7.3 High
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-9h9g-xpmp-46vg
Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally.
Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally.
- Record
GHSA-9h9g-xpmp-46vg- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-122, CWE-787
- Updated
- 2026-11-02
NVD
Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally.
- Record
CVE-2026-21248- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-122, CWE-787
- Updated
- 2026-11-02
Affected products
- microsoft windows 10 version 1607
- microsoft windows 10 version 1809
- microsoft windows 10 version 21h2
- microsoft windows 10 version 22h2
- microsoft windows 11 version 22h3
- microsoft windows 11 version 23h2
- microsoft windows 11 version 24h2
- microsoft windows 11 version 25h2
- microsoft windows 11 version 26h1
- microsoft windows server 2016
- microsoft windows server 2016 (server core installation)
- microsoft windows server 2019
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- microsoft windows server 2019 (server core installation)
- microsoft windows server 2022
- microsoft windows server 2022, 23h2 edition (server core installation)
- microsoft windows server 2025
- microsoft windows server 2025 (server core installation)
- microsoft windows 10 1607
- microsoft windows 10 1809
- microsoft windows 10 21h2
- microsoft windows 10 22h2
- microsoft windows 11 23h2
- microsoft windows 11 24h2
- microsoft windows 11 25h2
- microsoft windows server 2022 23h2
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Exploit-DB | Windows 11 25H2 - Heap Overflow | 2026-04-30 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, Exploit-DB, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-21248 is a high vulnerability (CVSS 7.3) in Microsoft Windows 10 Version 1607, published February 10, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 1.31%, the 71st percentile. No source names a fixed version.