CVE-2026-25178
📋 TL;DR
This vulnerability is a use-after-free flaw in the Windows Ancillary Function Driver for WinSock that allows an authenticated attacker to escalate privileges locally. It affects Windows systems with the vulnerable driver component. Attackers need local access to exploit this vulnerability.
💻 Affected Systems
- Windows Ancillary Function Driver for WinSock (afd.sys)
⚠️ 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
An attacker with local access could gain SYSTEM-level privileges, enabling complete system compromise, data theft, and persistence establishment.
Likely Case
Privilege escalation from standard user to administrator or SYSTEM privileges, allowing installation of malware, credential harvesting, and lateral movement.
If Mitigated
Limited impact if proper access controls, least privilege principles, and network segmentation are implemented.
🎯 Exploit Status
Exploitation requires local access and understanding of Windows kernel memory management. Use-after-free vulnerabilities can be challenging to exploit reliably.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft's monthly security updates for the specific KB number
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-25178
Restart Required: Yes
Instructions:
1. Apply the latest Windows security updates from Microsoft. 2. Restart the system to complete the installation. 3. Verify the patch is applied using Windows Update history.
🔧 Temporary Workarounds
Restrict local access
windowsLimit physical and remote access to vulnerable systems to trusted users only
Implement least privilege
windowsEnsure users operate with minimal necessary privileges to reduce impact of successful exploitation
🧯 If You Can't Patch
- Implement strict access controls and monitor for privilege escalation attempts
- Segment networks to limit lateral movement from compromised systems
🔍 How to Verify
Check if Vulnerable:
Check Windows Update history for missing security patches or use Microsoft's security update guideCheck Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify the specific KB patch is installed via Windows Update history or systeminfo command📡 Detection & Monitoring
Log Indicators:
- Unexpected privilege escalation events
- Suspicious process creation with SYSTEM privileges
- Kernel driver loading anomalies
Network Indicators:
- Unusual outbound connections from previously low-privilege accounts
SIEM Query:
EventID=4688 AND NewProcessName="*" AND SubjectUserName!="SYSTEM" AND TokenElevationType="%%1938"