Windows Hyper-V
CVE-2018-0961 — Hyper-V vSMB Remote Code Execution Vulnerability
Executive Summary
A remote code execution vulnerability exists when Windows Hyper-V on a host server fails to properly validate vSMB packet data. An attacker who successfully exploited these vulnerabilities could execute arbitrary code on a target operating system. To exploit these vulnerabilities, an attacker running inside a virtual machine could run a specially crafted application that could cause the Hyper-V host operating system to execute arbitrary code. The update addresses the vulnerabilities by correcting how Windows Hyper-V validates vSMB packet data.
Overview
7.6
CVSS HIGH
Critical
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
CVSS Vector
ATTACK VECTOR
Adjacent
ATTACK COMPLEXITY
High
PRIVILEGES REQUIRED
High
USER INTERACTION
None
SCOPE
Changed
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Proof-of-Concept
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 6.8
EPSS Score
0.03227
probability of exploitation in the next 30 days
0.87136 percentile - updated 2026-08-14
View on FIRST.org
Affected Products
8 affected products
| Product | KB Article | Severity | Impact | Restart Required |
|---|---|---|---|---|
| Windows 10 Version 1607 for x64-based Systems | 4103723 (Security Update) |
Critical | Remote Code Execution | Yes |
| Windows 10 Version 1703 for x64-based Systems | 4103731 (Security Update) |
Critical | Remote Code Execution | Yes |
| Windows 10 Version 1709 for x64-based Systems | 4103727 (Security Update) |
Critical | Remote Code Execution | Yes |
| Windows 10 Version 1803 for x64-based Systems | 4103721 (Security Update) |
Critical | Remote Code Execution | Yes |
| Windows Server 2016 | 4103723 (Security Update) |
Critical | Remote Code Execution | Yes |
| Windows Server 2016 (Server Core installation) | 4103723 (Security Update) |
Critical | Remote Code Execution | Yes |
| Windows Server, version 1709 (Server Core Installation) | 4103727 (Security Update) |
Critical | Remote Code Execution | Yes |
| Windows Server, version 1803 (Server Core Installation) | 4103721 (Security Update) |
Critical | Remote Code Execution | Yes |
Patches
4 patches
| Article | Type | Restart |
|---|---|---|
4103723 |
Security Update | Yes |
4103731 |
Security Update | Yes |
4103727 |
Security Update | Yes |
4103721 |
Security Update | Yes |
Exploits & PoC
No public exploit or PoC has been linked for this CVE yet. When available, references are sourced from public repositories and may be unverified or non-functional — review carefully before use.
Detection Rules
No public Sigma or Nuclei detection rule has been mapped to this CVE yet. Coverage is concentrated on exploited / high-profile vulnerabilities; check SigmaHQ for updates.
Acknowledgments
Matthew G. McGovern, Windows Security Team
References
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