CVE-2025-47999
📋 TL;DR
A missing synchronization vulnerability in Windows Hyper-V allows an authenticated attacker on an adjacent network to cause a denial of service. This affects Windows systems running Hyper-V virtualization. The attacker must have network access to the Hyper-V host.
💻 Affected Systems
- Windows Hyper-V
📦 What is this software?
Windows 10 1607 by Microsoft
Windows 10 1809 by Microsoft
Windows 10 21h2 by Microsoft
Windows 10 22h2 by Microsoft
Windows 11 22h2 by Microsoft
Windows 11 23h2 by Microsoft
Windows 11 24h2 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete denial of service to Hyper-V virtual machines, disrupting critical workloads and services.
Likely Case
Temporary service disruption affecting virtual machine availability and performance.
If Mitigated
Minimal impact with proper network segmentation and access controls limiting adjacent network exposure.
🎯 Exploit Status
Requires authorized access and adjacent network positioning. No public exploit code known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: To be determined via Windows Update
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-47999
Restart Required: Yes
Instructions:
1. Apply latest Windows security updates via Windows Update. 2. Restart affected Hyper-V hosts. 3. Verify patch installation via Windows Update history.
🔧 Temporary Workarounds
Network Segmentation
allIsolate Hyper-V management networks from general user/application networks
Access Control
allRestrict network access to Hyper-V hosts to authorized management systems only
🧯 If You Can't Patch
- Implement strict network segmentation to limit adjacent network access
- Monitor Hyper-V host performance and availability for signs of DoS attacks
🔍 How to Verify
Check if Vulnerable:
Check if system is running Hyper-V and has not applied the security patch for CVE-2025-47999Check Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify Windows Update history shows the security patch for CVE-2025-47999 is installed📡 Detection & Monitoring
Log Indicators:
- Hyper-V service crashes
- Unexpected virtual machine restarts
- Performance degradation alerts
Network Indicators:
- Unusual network traffic patterns to Hyper-V management interfaces
SIEM Query:
EventID=1000 OR EventID=1001 OR EventID=41 Source="Hyper-V*"