CVE-2026-25170
📋 TL;DR
This CVE describes a use-after-free vulnerability in Windows Hyper-V that allows an authenticated attacker to escalate privileges on the local system. It affects Windows systems running Hyper-V virtualization. Attackers must already have some level of access to exploit this vulnerability.
💻 Affected Systems
- Windows Hyper-V
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise where an authenticated attacker gains SYSTEM/administrator privileges, potentially leading to full control of the host operating system and all virtual machines.
Likely Case
Local privilege escalation allowing an attacker with standard user access to gain administrative privileges on the host system.
If Mitigated
Limited impact if proper access controls and monitoring are in place, though privilege escalation would still be possible for authenticated attackers.
🎯 Exploit Status
Requires authenticated access and knowledge of Hyper-V internals. Use-after-free vulnerabilities typically require precise timing and memory manipulation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft Security Update Guide for specific patch versions
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-25170
Restart Required: Yes
Instructions:
1. Apply the latest Windows security updates from Microsoft
2. For Windows Server, install updates via Windows Update or WSUS
3. Restart the system after patch installation
4. Verify Hyper-V services are running properly post-patch
🔧 Temporary Workarounds
Disable Hyper-V
windowsDisable the Hyper-V feature if not required for business operations
Disable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V-All
Restrict Hyper-V Management Access
windowsLimit which users can manage Hyper-V to reduce attack surface
Use Group Policy to restrict Hyper-V administrator privileges
🧯 If You Can't Patch
- Implement strict access controls and limit who has login access to Hyper-V hosts
- Enable enhanced monitoring and logging for Hyper-V management activities
🔍 How to Verify
Check if Vulnerable:
Check if Hyper-V is enabled and compare Windows version against patched versions in Microsoft advisoryCheck Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify Windows Update history shows the relevant security update installed and Hyper-V services are running📡 Detection & Monitoring
Log Indicators:
- Unusual Hyper-V service crashes or restarts
- Suspicious process creation from Hyper-V related executables
- Failed privilege escalation attempts in security logs
Network Indicators:
- Unusual Hyper-V management traffic patterns
SIEM Query:
EventID=4688 AND (ProcessName LIKE '%vmwp%' OR ProcessName LIKE '%vmms%') AND NewProcessName LIKE '%cmd%' OR NewProcessName LIKE '%powershell%'