CVE-2025-26684
📋 TL;DR
This vulnerability in Microsoft Defender for Endpoint allows an authorized attacker to manipulate file paths to achieve local privilege escalation. It affects organizations using Microsoft Defender for Endpoint with vulnerable configurations. Attackers must already have some level of access to the system to exploit this weakness.
💻 Affected Systems
- Microsoft Defender for Endpoint
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
An authenticated attacker gains full administrative control over the endpoint, potentially compromising the entire device and accessing sensitive data.
Likely Case
An authorized user with limited privileges elevates to higher privileges, enabling them to install malware, modify system settings, or access restricted resources.
If Mitigated
With proper access controls and monitoring, exploitation attempts are detected and blocked before privilege escalation occurs.
🎯 Exploit Status
Exploitation requires authorized access and knowledge of the specific file path manipulation technique.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft Security Update Guide for specific patch version
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-26684
Restart Required: Yes
Instructions:
1. Open Windows Update settings. 2. Check for updates. 3. Install all available security updates. 4. Restart the system when prompted.
🔧 Temporary Workarounds
Restrict local user privileges
windowsImplement least privilege access controls to limit what authorized users can do on endpoints
Enable Defender for Endpoint tamper protection
windowsPrevent unauthorized modifications to Defender for Endpoint components
🧯 If You Can't Patch
- Implement strict access controls and monitor for unusual privilege escalation attempts
- Segment networks to limit lateral movement if endpoint is compromised
🔍 How to Verify
Check if Vulnerable:
Check Defender for Endpoint version against Microsoft's patched version list in the advisoryCheck Version:
Get-MpComputerStatus | Select-Object AMProductVersionVerify Fix Applied:
Verify Windows Update shows no pending security updates and Defender for Endpoint is running latest version📡 Detection & Monitoring
Log Indicators:
- Unusual file path manipulation in Defender logs
- Unexpected privilege escalation events
- Suspicious process creation with elevated privileges
Network Indicators:
- None - this is a local attack
SIEM Query:
EventID=4688 AND NewProcessName contains * AND SubjectUserName != SYSTEM AND TokenElevationType != %%1936