Microsoft Windows Advanced Rasterization Platform: Local privilege escalation via heap overflow

Summary

A heap-based buffer overflow in the Windows Advanced Rasterization Platform allows an authorized local user to elevate privileges on affected Windows 10, Windows 11 and Windows Server systems. The attacker needs valid low-privilege access to the system, for example through a compromised user account or malware running as a standard user. The CVSS score is 8.8 (high), and the impact on confidentiality, integrity and availability is rated high.

Affected

• Windows 10 Version 1809 and Windows Server 2019 (including Server Core): 10.0.17763.0 to before 10.0.17763.9376
• Windows 10 Version 21H2: 10.0.19044.0 to before 10.0.19044.7807
• Windows 10 Version 22H2: 10.0.19045.0 to before 10.0.19045.7807
• Windows 11 Version 23H2: 10.0.22631.0 to before 10.0.22631.7652
• Windows 11 Version 24H2: 10.0.26100.0 to before 10.0.26100.9711
• Windows 11 Version 25H2: 10.0.26200.0 to before 10.0.26200.9711
• Windows 11 Version 26H1: 10.0.28000.0 to before 10.0.28000.3231
• Windows 11 Version 26H2: 10.0.26300.0 to before 10.0.26300.9711
• Windows Server 2022: 10.0.20348.0 to before 10.0.20348.5761
• Windows Server 2025 (including Server Core): 10.0.26100.0 to before 10.0.26100.33650

Fixed in

• Install the Microsoft security update from November 2026 (cumulative update) for your Windows version.
• First fixed builds according to the CVE record: 10.0.17763.9376, 10.0.19044.7807, 10.0.19045.7807, 10.0.22631.7652, 10.0.26100.9711, 10.0.26200.9711, 10.0.28000.3231, 10.0.26300.9711, 10.0.20348.5761, 10.0.26100.33650 (Server 2025).
• Verify the fixed builds and KB article numbers on the MSRC Security Update Guide before rollout.

Workaround

Unknown. No vendor workaround or mitigation was found in the available sources. Applying the security update is the primary remedy.

Exploitation

• No evidence of in-the-wild exploitation or public proof-of-concept code was found at publication.
• CISA SSVC assessment: exploitation none, not automatable, technical impact total.
• NVD analysis was still pending at the time of research.

Our recommendation

• Apply the November 2026 Windows security update to all affected systems, starting with multi-user servers, terminal servers (RDS) and shared workstations.
• Check whether any systems run Windows 10 Version 1809, 21H2 or 22H2 that are no longer supported and plan their upgrade.
• Limit local logon rights and restrict standard-user access to sensitive systems.
• Monitor for unexpected privilege changes and new administrative accounts on endpoints and servers.

Public exploits iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).

PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.

Research sources

• Microsoft Security Update Guide: CVE-2026-118228 msrc.microsoft.com
• CVE Record CVE-2026-118228 (CVE Program) www.cve.org
• Tenable: Microsoft November 2026 Patch Tuesday www.tenable.com
• Strix: CVE-2026-118228 (aggregator, unverified) www.strix.ai

Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 10 Nov 2026, 22:15.