Windows: Local elevation of privilege in Desktop Window Manager
Summary
A local elevation of privilege vulnerability (CVE-2026-70228, CWE-125 out-of-bounds read) exists in the Desktop Window Manager component of Windows 10 1809 and other supported Windows versions and Windows Server releases. An attacker who already has a low-privileged logon on the system can exploit it to gain higher privileges, potentially up to SYSTEM. It is not remotely exploitable and requires no user interaction. Microsoft has released fixes.
Affected
- Windows 10 Version 1809 (builds below 10.0.17763.9376)
- Windows 10 Version 21H2 (builds below 10.0.19044.7807)
- Windows 10 Version 22H2 (builds below 10.0.19045.7807)
- Windows 11 Version 23H2 (builds below 10.0.22631.7652)
- Windows 11 Version 24H2 (builds below 10.0.26100.9711)
- Windows 11 Version 25H2 (builds below 10.0.26200.9711)
- Windows 11 Version 26H1 (builds below 10.0.28000.3231)
- Windows 11 Version 26H2 (builds below 10.0.26300.9711)
- Windows Server 2019, including Server Core (builds below 10.0.17763.9376)
- Windows Server 2022 (builds below 10.0.20348.5761)
- Windows Server 2025, including Server Core (builds below 10.0.26100.33650)
Fixed in
- Windows 10 1809: 10.0.17763.9376
- Windows 10 21H2: 10.0.19044.7807
- Windows 10 22H2: 10.0.19045.7807
- Windows 11 23H2: 10.0.22631.7652
- Windows 11 24H2: 10.0.26100.9711
- Windows 11 25H2: 10.0.26200.9711
- Windows 11 26H1: 10.0.28000.3231
- Windows 11 26H2: 10.0.26300.9711
- Windows Server 2019: 10.0.17763.9376
- Windows Server 2022: 10.0.20348.5761
- Windows Server 2025: fixed build unknown, verify on the MSRC Security Update Guide
Workaround
Unknown. No mitigation was published; installing the security update is the available fix.
Exploitation
- Not known to be exploited in the wild.
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
- Not listed in the CISA KEV catalogue.
- No public proof of concept found; this does not prove that none exists.
- EPSS score 0.00364.
Our recommendation
- Install the October 2026 Windows security update on all affected systems, starting with multi-user systems, Remote Desktop and terminal servers, and kiosks.
- Verify the installed build number and the KB number on the MSRC Security Update Guide before rollout.
- Review local administrator rights and restrict unnecessary local logons.
- Monitor for suspicious privilege escalation and unusual process activity on endpoints.
- Priority: medium; higher where several users share a Windows 10 1809 system.
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Desktop Window Manager
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5127648, KB5126646, KB5126651, KB5126657, KB5126655, KB5126653
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-70228 msrc.microsoft.com
- Vulners: CVE-2026-70228 vulners.com
- Vulners NVD record: CVE-2026-70228 vulners.com
- Strix: CVE-2026-70228 www.strix.ai
- OpenCVE: CVE-2026-70228 app.opencve.io
- Tenable plugin 365475 www.tenable.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 2 Nov 2026, 03:56.
Original description (NVD)
Out-of-bounds read in Desktop Window Manager allows an authorized attacker to elevate privileges locally.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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