Windows 10 1809: Use-after-free in Desktop Window Manager allows privilege escalation
Summary
A use-after-free vulnerability (CWE-416) in the Desktop Window Manager of Windows 10 version 1809 and Windows Server 2019 allows an authorized local user to elevate privileges. An attacker needs a valid low-privileged account or an existing foothold on the system, but then can gain high impact on confidentiality, integrity and availability. The vulnerability is not reachable directly from the internet.
Affected
- Windows 10 Version 1809: builds 10.0.17763.0 to below 10.0.17763.9376
- Windows Server 2019 and Server 2019 (Server Core installation): builds 10.0.17763.0 to below 10.0.17763.9376
- Other Windows versions are also listed in the CVE record (for example Windows 10 21H2/22H2, Windows 11, Windows Server 2022/2025); this entry covers 1809 and Server 2019 only.
Fixed in
- Fixed in the October 2026 security update. Per the CVE record, build 10.0.17763.9376 and later are not affected.
- The KB number for 1809 and Server 2019 is reported as KB5126651 by a third-party source; confirm it on the Microsoft Security Update Guide before deployment.
Workaround
- Unknown. No workaround is documented in the sources reviewed; patching is the practical mitigation.
Exploitation
- CISA SSVC: exploitation none, automatable no, technical impact total.
- Not listed in the CISA KEV catalogue at the time of research.
- No public proof-of-concept or in-the-wild exploitation found in the sources reviewed. Microsoft's exploited and publicly disclosed flags could not be verified.
Our recommendation
- Install the October 2026 cumulative update on all Windows 10 1809 and Windows Server 2019 systems, prioritising multi-user systems, terminal servers and servers.
- Verify the support status of each 1809 device, because unsupported builds may receive no fix.
- Limit local logon rights to trusted users and monitor for unexpected privilege changes until patched.
- Recheck the MSRC advisory and CISA KEV for updates on exploitation.
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)
- KB5126651, KB5126657, KB5126655, KB5126653, KB5127648, KB5126646
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-96108 msrc.microsoft.com
- OpenCVE: CVE-2026-96108 app.opencve.io
- Vulners CVE listing: CVE-2026-96108 vulners.com
- Vulners VulnCheck/CISA SSVC data: CVE-2026-96108 vulners.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, 01:03.
Original description (NVD)
Use after free 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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