CVE-2025-26675
📋 TL;DR
This vulnerability allows an authorized attacker with local access to exploit an out-of-bounds read in Windows Subsystem for Linux to elevate privileges. Attackers could gain higher system permissions than originally granted. This affects Windows systems running WSL with vulnerable versions.
💻 Affected Systems
- Windows Subsystem for Linux (WSL)
📦 What is this software?
Windows 10 21h2 by Microsoft
Windows 10 22h2 by Microsoft
Windows 11 22h2 by Microsoft
Windows 11 23h2 by Microsoft
Windows 11 24h2 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with SYSTEM/root privileges, allowing complete control over the Windows host and all WSL instances.
Likely Case
Local privilege escalation from standard user to administrator/root, enabling installation of malware, data theft, and persistence mechanisms.
If Mitigated
Limited impact with proper privilege separation, application control policies, and restricted user permissions.
🎯 Exploit Status
Requires authorized local access. CWE-125 vulnerabilities typically require specific conditions to trigger reliably.
🛠️ 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-2025-26675
Restart Required: Yes
Instructions:
1. Open Windows Update Settings. 2. Click 'Check for updates'. 3. Install all available security updates. 4. Restart when prompted.
🔧 Temporary Workarounds
Disable WSL
windowsCompletely disable Windows Subsystem for Linux if not required
wsl --shutdown
dism.exe /online /disable-feature /featurename:Microsoft-Windows-Subsystem-Linux
Restrict WSL Access
windowsLimit which users can access WSL through group policy
🧯 If You Can't Patch
- Implement strict least privilege principles - ensure no users have unnecessary local access
- Enable application control policies to restrict execution of unauthorized binaries
🔍 How to Verify
Check if Vulnerable:
Check Windows Update history for missing security patches related to WSLCheck Version:
wsl --versionVerify Fix Applied:
Verify the latest Windows cumulative updates are installed and check WSL version📡 Detection & Monitoring
Log Indicators:
- Unusual privilege escalation events in Windows Security logs
- Suspicious WSL process creation with elevated privileges
Network Indicators:
- Local privilege escalation doesn't typically generate network traffic
SIEM Query:
EventID=4688 AND NewProcessName LIKE '%wsl%' AND SubjectUserName!=TargetUserName