Local code execution via undisclosed heap overflow
Published Feb 10, 2026 · Updated Feb 10, 2026
Heap-based buffer overflow in Microsoft Windows Hyper-V allows local users to execute code through a crafted local interaction. Microsoft has not published the affected Hyper-V code locus, the malformed input that reaches it, or the incorrect heap operation. Exploitation requires low local privileges and user interaction, and successful exploitation grants code execution on the affected Windows system.
Summary
What happened
Heap-based buffer overflow in Microsoft Windows Hyper-V allows local users to execute code through a crafted local interaction. Microsoft has not published the affected Hyper-V code locus, the malformed input that reaches it, or the incorrect heap operation. Exploitation requires low local privileges and user interaction, and successful exploitation grants code execution on the affected Windows system.
The record
- CVE
- CVE-2026-21244
- Published
- Feb 10, 2026
- Updated
- Feb 10, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-122, CWE-787, T1203
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 10, 2026CVE publishedPublication date reported by the CVE source.
- Feb 10, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.17763.0 <10.0.17763.8389
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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