CVE-2026-25165
📋 TL;DR
A null pointer dereference vulnerability in Windows Performance Counters allows authenticated attackers to execute arbitrary code with elevated privileges on affected systems. This affects Windows systems where an attacker has local access and can trigger the vulnerability through specially crafted requests. The vulnerability enables privilege escalation from a standard user account to SYSTEM-level access.
💻 Affected Systems
- Microsoft Windows
⚠️ 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 with SYSTEM privileges, enabling installation of persistent malware, credential theft, and lateral movement across the network.
Likely Case
Local privilege escalation allowing attackers to bypass security controls, install additional malware, and access sensitive system resources.
If Mitigated
Limited impact with proper access controls, network segmentation, and endpoint protection that can detect and block exploitation attempts.
🎯 Exploit Status
Exploitation requires local access and authentication. The vulnerability is in a core Windows component, making reliable exploitation non-trivial but feasible for skilled attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: To be determined via Microsoft's monthly security updates
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-25165
Restart Required: Yes
Instructions:
1. Check Microsoft Security Update Guide for CVE-2026-25165. 2. Apply the appropriate Windows security update for your version. 3. Restart the system as required. 4. Verify the update was successfully installed.
🔧 Temporary Workarounds
Restrict Performance Counter Access
windowsLimit which users can access Windows Performance Counters through group policy or registry settings
reg add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Perflib" /v "DisablePerformanceCounters" /t REG_DWORD /d 1 /f
Implement Least Privilege Access
allEnsure users only have necessary permissions and cannot run arbitrary code
🧯 If You Can't Patch
- Implement strict access controls to limit who can log into affected systems
- Deploy endpoint detection and response (EDR) solutions to monitor for privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check Windows Update history for the specific KB patch mentioned in Microsoft's advisory for CVE-2026-25165Check Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify the security update is installed via 'wmic qfe list' or 'Get-Hotfix' in PowerShell and check for the relevant KB number📡 Detection & Monitoring
Log Indicators:
- Event ID 4688 with suspicious parent processes accessing performance counters
- Unexpected privilege escalation events in security logs
- Process creation from non-standard locations with SYSTEM privileges
Network Indicators:
- Not applicable - local exploitation only
SIEM Query:
EventID=4688 AND (NewProcessName="*perf*" OR ParentProcessName="*perf*") AND SubjectUserName!="SYSTEM"