CVE-2026-25176
📋 TL;DR
This vulnerability allows an authenticated attacker to escalate privileges on Windows systems by exploiting improper access control in the Ancillary Function Driver for WinSock. It affects Windows systems where the attacker already has some level of access. The impact is local privilege escalation, not remote code execution.
💻 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 standard user privileges gains SYSTEM/administrator privileges, enabling complete system compromise, credential theft, persistence installation, and lateral movement.
Likely Case
Malware or malicious users escalate privileges to bypass security controls, install additional payloads, or access protected resources.
If Mitigated
With proper patch management and least privilege principles, impact is limited to isolated systems with minimal lateral movement potential.
🎯 Exploit Status
Requires authenticated access and local code execution. Kernel driver vulnerabilities typically require careful exploitation to avoid system crashes.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft Security Update Guide for specific KB numbers
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-25176
Restart Required: Yes
Instructions:
1. Apply latest Windows security updates via Windows Update. 2. For enterprise environments, deploy patches through WSUS or SCCM. 3. Verify patch installation with systeminfo or Get-HotFix.
🔧 Temporary Workarounds
Restrict local user privileges
windowsImplement least privilege principles to limit impact if exploitation occurs
Enable Windows Defender Exploit Guard
windowsUse exploit protection to make exploitation more difficult
🧯 If You Can't Patch
- Implement application control policies to prevent unauthorized code execution
- Segment networks to limit lateral movement from compromised systems
🔍 How to Verify
Check if Vulnerable:
Check Windows version and compare with Microsoft's affected versions list. Vulnerable if running unpatched affected Windows version.Check Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify Windows Update history shows the relevant security update installed, or check systeminfo for the specific KB patch.📡 Detection & Monitoring
Log Indicators:
- Unusual process creation with elevated privileges
- Suspicious kernel driver activity
- Security event 4688 with elevated token
Network Indicators:
- None - this is a local privilege escalation vulnerability
SIEM Query:
EventID=4688 AND NewProcessName CONTAINS 'cmd.exe' OR 'powershell.exe' AND SubjectLogonId != 0x3e7 AND TokenElevationType != %%1936