📄 Description (English)
Stack-based buffer overflow in Windows TCP/IP allows an authorized attacker to elevate privileges locally.
🤖 AI Executive Summary
CVE-2026-40399 is a stack-based buffer overflow in Windows TCP/IP stack affecting multiple Windows 10 versions, allowing authenticated local attackers to escalate privileges. With a CVSS score of 7.8 and no patch currently available, this vulnerability poses significant risk to Saudi organizations relying on Windows infrastructure. The lack of public exploits provides a temporary window for defensive measures before weaponization.
📄 Description (Arabic)
🤖 AI Intelligence Analysis Analyzed: May 19, 2026 00:17
🇸🇦 Saudi Arabia Impact Assessment
This vulnerability directly impacts Saudi government agencies, banking sector (SAMA-regulated institutions), healthcare facilities, and critical infrastructure operators heavily dependent on Windows 10 systems. Government entities using Windows 10 for administrative functions face elevated privilege escalation risks. Banking and financial institutions are particularly vulnerable as TCP/IP stack integrity is critical for secure transactions. Energy sector organizations and telecommunications providers (STC, Mobily) operating Windows-based network infrastructure face potential lateral movement risks. The vulnerability requires local access, limiting exposure but creating insider threat concerns in organizations with inadequate access controls.
🏢 Affected Saudi Sectors
Government & Public Administration
Banking & Financial Services
Healthcare & Medical Institutions
Energy & Utilities (ARAMCO, SEC)
Telecommunications (STC, Mobily, Zain)
Education
Critical Infrastructure
Defense & Security
🎯 MITRE ATT&CK Techniques
T1548.004 — Abuse Elevation Control Mechanism: Bypass User Account Control
T1548 — Abuse Elevation Control Mechanism
T1134 — Access Token Manipulation
T1547 — Boot or Logon Autostart Execution
T1547.001 — Registry Run Keys / Startup Folder
T1053 — Scheduled Task/Job
T1574 — Hijack Execution Flow
T1574.008 — DLL Search Order Hijacking
⚖️ Saudi Risk Score (AI)
7.8
/ 10.0
🔧 Remediation Steps (English)
IMMEDIATE ACTIONS:
1. Inventory all Windows 10 systems (versions 1607, 1809, 21H2, 22H2) across your organization
2. Implement strict local access controls and disable unnecessary local accounts
3. Enable Windows Defender Exploit Guard and Attack Surface Reduction rules
4. Monitor for suspicious privilege escalation attempts
COMPENSATING CONTROLS (until patch available):
1. Restrict local administrative access using Group Policy (GPO) - disable local admin accounts where possible
2. Implement application whitelisting to prevent unauthorized process execution
3. Enable Windows Defender Application Guard for critical systems
4. Deploy endpoint detection and response (EDR) solutions with behavioral monitoring
5. Enforce multi-factor authentication for sensitive systems
6. Disable unnecessary network services and TCP/IP features via Group Policy
DETECTION RULES:
1. Monitor Event ID 4688 (Process Creation) for unusual TCP/IP stack interactions
2. Alert on failed privilege escalation attempts (Event ID 4673)
3. Monitor for abnormal memory access patterns in tcpip.sys processes
4. Track unauthorized local account creation and privilege additions
5. Implement YARA rules targeting stack overflow exploitation patterns
PATCHING STRATEGY:
1. Subscribe to Microsoft Security Update Guide for CVE-2026-40399 patch release
2. Establish expedited patching timeline once patch becomes available
3. Prioritize critical systems: government networks, banking infrastructure, healthcare systems
4. Test patches in isolated environments before production deployment
🔧 خطوات المعالجة (العربية)
الإجراءات الفورية:
1. قم بحصر جميع أنظمة Windows 10 (الإصدارات 1607 و 1809 و 21H2 و 22H2) عبر مؤسستك
2. تطبيق ضوابط وصول محلية صارمة وتعطيل الحسابات المحلية غير الضرورية
3. تفعيل Windows Defender Exploit Guard وقواعد تقليل سطح الهجوم
4. مراقبة محاولات تصعيد الامتيازات المريبة
الضوابط البديلة (حتى توفر التصحيح):
1. تقييد الوصول الإداري المحلي باستخدام Group Policy - تعطيل حسابات المسؤول المحلية حيث أمكن
2. تطبيق قائمة بيضاء للتطبيقات لمنع تنفيذ العمليات غير المصرح بها
3. تفعيل Windows Defender Application Guard للأنظمة الحرجة
4. نشر حلول الكشف والاستجابة للنقاط النهائية (EDR) مع المراقبة السلوكية
5. فرض المصادقة متعددة العوامل للأنظمة الحساسة
6. تعطيل الخدمات والميزات غير الضرورية في TCP/IP عبر Group Policy
قواعد الكشف:
1. مراقبة معرف الحدث 4688 (إنشاء العملية) للتفاعلات غير المعتادة مع مكدس TCP/IP
2. تنبيهات محاولات تصعيد الامتيازات الفاشلة (معرف الحدث 4673)
3. مراقبة أنماط الوصول إلى الذاكرة غير الطبيعية في عمليات tcpip.sys
4. تتبع إنشاء الحسابات المحلية غير المصرح بها وإضافات الامتيازات
5. تطبيق قواعد YARA التي تستهدف أنماط استغلال تجاوز السعة
استراتيجية التصحيح:
1. الاشتراك في دليل تحديث أمان Microsoft للحصول على إصدار تصحيح CVE-2026-40399
2. إنشاء جدول زمني معجل للتصحيح بمجرد توفر التصحيح
3. إعطاء الأولوية للأنظمة الحرجة: الشبكات الحكومية والبنية التحتية المصرفية والأنظمة الصحية
4. اختبار التصحيحات في بيئات معزولة قبل نشرها في الإنتاج
📋 Regulatory Compliance Mapping
🟢 NCA ECC 2024
ECC 2024 - 5.1.1 Access Control Policy
ECC 2024 - 5.2.1 User Registration and De-registration
ECC 2024 - 5.3.1 User Access Rights
ECC 2024 - 6.1.1 Event Logging
ECC 2024 - 6.2.1 Protection of Log Information
ECC 2024 - 8.1.1 Operational Change Management
🔵 SAMA CSF
SAMA CSF - Governance & Risk Management (GRM-01: Risk Assessment)
SAMA CSF - Information Security (IS-01: Information Security Policy)
SAMA CSF - Access Control (AC-01: Access Control Policy)
SAMA CSF - System Development & Maintenance (SDM-01: Change Management)
SAMA CSF - Monitoring & Incident Management (MIM-01: Security Monitoring)
🟡 ISO 27001:2022
ISO 27001:2022 - A.5.1 Policies for information security
ISO 27001:2022 - A.5.15 Access control
ISO 27001:2022 - A.5.16 Identification and authentication
ISO 27001:2022 - A.5.23 Information security for supplier relationships
ISO 27001:2022 - A.8.1 User endpoint devices
ISO 27001:2022 - A.8.2 Privileged access rights
ISO 27001:2022 - A.8.3 Information access restriction
🟣 PCI DSS v4.0.1
PCI DSS 4.0 - Requirement 1: Firewall and network access control
PCI DSS 4.0 - Requirement 2: Default security parameters
PCI DSS 4.0 - Requirement 6: Develop and maintain secure systems
PCI DSS 4.0 - Requirement 7: Restrict access to cardholder data
PCI DSS 4.0 - Requirement 8: Identify and authenticate access
📦 Affected Products / CPE 23 entries
microsoft:windows_10_1607
microsoft:windows_10_1607
microsoft:windows_10_1809
microsoft:windows_10_1809
microsoft:windows_10_21h2
microsoft:windows_10_21h2
microsoft:windows_10_21h2
microsoft:windows_10_22h2
microsoft:windows_10_22h2
microsoft:windows_10_22h2
microsoft:windows_11_23h2
microsoft:windows_11_23h2
microsoft:windows_11_24h2
microsoft:windows_11_24h2
microsoft:windows_11_25h2
microsoft:windows_11_25h2
microsoft:windows_11_26h1
microsoft:windows_11_26h1
microsoft:windows_server_2016
microsoft:windows_server_2019
microsoft:windows_server_2022
microsoft:windows_server_2022_23h2
microsoft:windows_server_2025