Microsoft Windows: Local privilege escalation via integer overflow in Overlay Filter

Summary

Microsoft Windows contains an integer overflow or wraparound in the Windows Overlay Filter component. An authorized local attacker with low privileges can exploit it to elevate privileges, which may lead to full control of the affected system. No user interaction is required, but the attacker needs an existing local user account or foothold. Microsoft and NVD rate the issue as High (CVSS 3.1 7.8).

Affected

• Windows 10 Version 1607: below 10.0.14393.9612
• Windows Server 2016: below 10.0.14393.9612
• Windows 10 Version 1809: below 10.0.17763.9376
• Windows Server 2019: below 10.0.17763.9376 (build per CNA data, see research notes)
• Windows 10 Version 21H2: below 10.0.19044.7807
• Windows 10 Version 22H2: below 10.0.19045.7807
• Windows 11 Version 23H2: below 10.0.22631.7652
• Windows 11 Version 24H2: below 10.0.26100.9711
• Windows 11 Version 25H2: below 10.0.26200.9711
• Windows 11 Version 26H1: below 10.0.28000.3231
• Windows 11 Version 26H2: below 10.0.26300.9711
• Windows Server 2012 (including Server Core): below 6.2.9200.26434
• Windows Server 2012 R2 (including Server Core): below 6.3.9600.23470
• Windows Server 2025: 10.0.26100.33650 (build per CNA data, see research notes)

Fixed in

• Windows 10 Version 1607 and Windows Server 2016: build 10.0.14393.9612 or later
• Windows 10 Version 1809 and Windows Server 2019: build 10.0.17763.9376 or later
• Windows 10 Version 21H2: build 10.0.19044.7807 or later
• Windows 10 Version 22H2: build 10.0.19045.7807 or later
• Windows 11 Version 23H2: build 10.0.22631.7652 or later
• Windows 11 Version 24H2: build 10.0.26100.9711 or later
• Windows 11 Version 25H2: build 10.0.26200.9711 or later
• Windows Server 2025: build 10.0.26100.33650 or later
• KB numbers per build: Unknown. Confirm them in the MSRC Security Update Guide.

Workaround

Unknown. The retrieved Microsoft advisory content does not list a workaround.

• Unverified generic hardening: restrict which local users can run or load the affected component, for example with least privilege or AppLocker. This is not confirmed by Microsoft.

Exploitation

• No evidence of exploitation in the wild was found in the consulted sources.
• No public proof of concept was found.
• EPSS: 0.00341.
• CISA SSVC assessment: Exploitation none, Automatable no, Technical Impact total.
• CISA KEV catalog status was not verified.

Our recommendation

• Install the security update for each affected build as soon as possible, starting with multi-user servers, terminal servers and shared PCs.
• Build a complete inventory, including older Windows 10 1607 and Windows Server 2016 systems, which are easy to miss.
• Confirm the KB number for each build in the MSRC Security Update Guide before rollout.
• Check the CISA KEV catalog before closing the ticket and monitor for exploitation reports.
• Restrict local accounts and limit untrusted logons on affected systems until patched.

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-2026-69957 msrc.microsoft.com
• CVE List (CNA JSON) via Vulners vulners.com
• Microsoft MSCVE record via Vulners vulners.com
• NVD record mirror via Vulners vulners.com
• Rapid7 record via Vulners (EPSS) vulners.com
• OpenCVE record app.opencve.io

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 2 Nov 2026, 04:35.