CVE-2026-21248 Windows Hyper-V Remote Code Execution Vulnerability
An authorized local attacker can execute arbitrary code via a heap-based buffer overflow in Windows Hyper-V.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-21248?
CVE-2026-21248 is a high-severity memory corruption vulnerability in Microsoft Windows 10 1607, published on 10 Feb 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally.
Which versions are affected by CVE-2026-21248?
It affects 12 products.
Products include Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2 and 6 more.
How do I fix CVE-2026-21248?
No fix has been published for CVE-2026-21248 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-21248 being exploited?
There is no known exploitation of CVE-2026-21248 in the wild and no public exploit code.
Public exploit code: 1 Exploit-DB entry.
Other vulnerabilities in Microsoft Windows 10 1607
- CVE-2026-33824 Microsoft Internet Key Exchange (IKE) Service Extensions Double Free
- CVE-2026-21510 Microsoft Windows Shell Protection Mechanism Failure
- CVE-2026-21513 Microsoft MSHTML Framework Protection Mechanism Failure
- CVE-2023-32049 Microsoft Windows Defender SmartScreen Security Feature Bypass
- CVE-2023-29360 Microsoft Streaming Service Untrusted Pointer Dereference
Sources
Also known as GHSA-9h9g-xpmp-46vg.