Security Vulnerability Report
中文
CVE-2026-20818 CVSS 6.2 MEDIUM

CVE-2026-20818

Published: 2026-01-13 18:16:09
Last Modified: 2026-01-14 20:32:15

Description

Insertion of sensitive information into log file in Windows Kernel allows an unauthorized attacker to disclose information locally.

CVSS Details

CVSS Score
6.2
Severity
MEDIUM
CVSS Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Configurations (Affected Products)

cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:* - VULNERABLE
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:* - VULNERABLE
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:* - VULNERABLE
cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:* - VULNERABLE
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:* - VULNERABLE
Windows 10 version 1809
Windows 10 version 1903
Windows 10 version 1909
Windows 10 version 2004
Windows 10 version 20H2
Windows 10 version 21H1
Windows 10 version 21H2
Windows 11 version 21H2
Windows 11 version 22H2
Windows Server 2019
Windows Server 2022

PoC / Exploit Code

⚠ For Security Research Only
The following code is for security research and authorized testing only.
python
# CVE-2026-20818 Windows Kernel Information Disclosure PoC # Author: Security Researcher # Note: This PoC demonstrates the vulnerability concept import os import sys import subprocess def check_vulnerability(): """ Check if the system is vulnerable to CVE-2026-20818 This vulnerability allows local attackers to read sensitive information from Windows Kernel logs """ print("[*] CVE-2026-20818 Windows Kernel Information Disclosure Check") print("[*] Target: Windows Kernel") print("[*] Vulnerability: Sensitive information insertion into log file") # Check Windows version try: result = subprocess.run(['systeminfo'], capture_output=True, text=True) print(f"\n[+] System Information:") for line in result.stdout.split('\n')[:5]: print(f" {line}") except Exception as e: print(f"[-] Error gathering system info: {e}") # Check for sensitive data in common log locations log_paths = [ r'C:\Windows\System32\winevt\Logs', r'C:\Windows\System32\config\SYSTEM', r'C:\Windows\Debug\mrt.log' ] print("\n[*] Checking accessible log files...") for path in log_paths: if os.path.exists(path): print(f"[+] Found: {path}") try: files = os.listdir(path) for f in files[:5]: print(f" - {f}") except PermissionError: print(f" [-] Access denied") # Check for kernel debug output print("\n[*] Checking kernel debug settings...") try: result = subprocess.run( ['reg', 'query', 'HKLM\\SYSTEM\\CurrentControlSet\\Control\\Session Manager\\Debug Print Filter'], capture_output=True, text=True ) if result.returncode == 0: print("[+] Debug Print Filter found") print(result.stdout) except: pass print("\n[*] Mitigation: Apply Microsoft security updates") print("[*] Reference: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20818") return True if __name__ == "__main__": if sys.platform != "win32": print("[-] This PoC is designed for Windows systems only") sys.exit(1) check_vulnerability()

References

Raw JSON Data

JSON
{"cve": {"id": "CVE-2026-20818", "sourceIdentifier": "[email protected]", "published": "2026-01-13T18:16:08.810", "lastModified": "2026-01-14T20:32:15.047", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Insertion of sensitive information into log file in Windows Kernel allows an unauthorized attacker to disclose information locally."}, {"lang": "es", "value": "Inserción de información sensible en un archivo de registro en el kernel de Windows permite a un atacante no autorizado divulgar información localmente."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N", "baseScore": 6.2, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.5, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-532"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.14393.8783", "matchCriteriaId": "A059E609-F8D4-4246-BDAE-0AEDED1744D2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.17763.8276", "matchCriteriaId": "A74970A1-CC81-4482-B465-8382B1544EF3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.20348.4648", "matchCriteriaId": "C4AA6991-DE34-48F6-AFD3-77CEE7FBB692"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.25398.2092", "matchCriteriaId": "BA5947E0-C44C-4517-A307-DA79752F30A8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.26100.7623", "matchCriteriaId": "C6BE8CAC-3A47-48FC-A0FD-F0F0ADD2A9CE"}]}]}], "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20818", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}