Windows Graphics Kernel: Heap-based buffer overflow allows local privilege escalation

Summary

A heap-based buffer overflow in the Windows Graphics Kernel allows an authorized local attacker to elevate privileges. The attacker must already be able to run code on the system with a low-privileged account, and the attack complexity is high. Successful exploitation would give full control over the affected machine.

Affected

• Windows 10 Version 1607 (10.0.14393.0 before 10.0.14393.9688)
• Windows 10 Version 1809 (10.0.17763.0 before 10.0.17763.9487)
• Windows 10 Version 21H2 (10.0.19044.0 before 10.0.19044.7846)
• Windows 10 Version 22H2 (10.0.19045.0 before 10.0.19045.7846)
• Windows 11 Version 23H2 (10.0.22631.0 before 10.0.22631.7711)
• Windows 11 Version 24H2 (10.0.26100.0 before 10.0.26100.9974)
• Windows 11 Version 25H2 (10.0.26200.0 before 10.0.26200.9974)
• Windows 11 Version 26H1 (10.0.28000.0 before 10.0.28000.3501)
• Windows 11 Version 26H2 (10.0.26300.0 before 10.0.26300.9974)
• Windows Server 2016, including Server Core (10.0.14393.0 before 10.0.14393.9688)
• Windows Server 2019, including Server Core (10.0.17763.0 before 10.0.17763.9487)
• Windows Server 2022 (10.0.20348.0 before 10.0.20348.5870)

Fixed in

Security updates contained in the Microsoft update for the affected builds listed above. Fixed build numbers are the first builds not listed as affected. KB article numbers: Unknown.

Workaround

Unknown.

Exploitation

• CISA SSVC: Exploitation none, not automatable, total technical impact.
• No evidence of in-the-wild exploitation or public proof of concept found.
• The CVE record's temporal vector includes E:U (unproven exploit maturity).

Our recommendation

• Install the November 2026 cumulative security update on all affected Windows 10, 11 and Server systems, starting with multi-user servers, terminal servers and shared PCs.
• Verify the build number of each system and check that out-of-support builds such as 1607, 1809, 21H2 and 22H2 are on a supported update path.
• Limit local logon rights on multi-user hosts and keep untrusted software off shared machines until patched.
• Check the MSRC advisory for the exploitation status before setting the patch priority.

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 Response Center: CVE-2026-95974 msrc.microsoft.com
• CVE Record CVE-2026-95974 www.cve.org
• Action1: Patch Tuesday November 2026 www.action1.com

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 11 Nov 2026, 07:58.