Windows Advanced Rasterization Platform: Local privilege escalation (stack overflow)

Summary

A stack-based buffer overflow in the Windows Advanced Rasterization Platform allows an authorized local attacker with low privileges to elevate privileges to a higher level. The CVSS score is 8.8 (High) with a changed scope. The attacker needs a local foothold, such as a standard user account or a compromised workstation, and no user interaction is required.

Affected

• Windows 10 Version 1809 (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 2019 incl. Server Core (10.0.17763.0 to before 10.0.17763.9376)
• Windows Server 2022 (10.0.20348.0 to before 10.0.20348.5761)
• Windows Server 2025 incl. Server Core (10.0.26100.0 to before 10.0.26100.33650)
• Source: CNA record excerpt. Please verify the full list on the MSRC page.

Fixed in

• Build numbers that include the fix are listed in the MSRC advisory. The versions above are the first fixed builds per the CNA record.
• KB article numbers: Unknown.

Workaround

Unknown. No vendor workaround was found for this CVE.

Exploitation

• No evidence of exploitation in the wild at publication.
• Microsoft's exploit maturity metric is 'Unproven'.
• No public proof of concept found.
• CISA KEV status: re-check, as the status was captured on publication day.

Our recommendation

• Install the Windows security update for each affected system as part of the normal patch cycle, and prioritize it because of the high CVSS score.
• Confirm the exact affected builds and KB numbers on the MSRC page.
• Limit local logon rights and keep local accounts to a minimum.
• Monitor for exploitation and public proof-of-concept code, and escalate if either appears.

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

• MSRC Security Update Guide: CVE-2026-118226 msrc.microsoft.com
• CVE Record CVE-2026-118226 (CNA: Microsoft) www.cve.org
• Strix CVE-2026-118226 (third-party aggregator) 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, 22:13.