Microsoft Windows DWM Core Library: Local privilege escalation via out-of-bounds read
Summary
An out-of-bounds read in the Windows DWM Core Library allows a local user with low privileges to elevate their rights, potentially to SYSTEM. The vulnerability affects Windows 10, Windows 11, Windows Server 2016, 2019, 2022 and 2025 in the builds listed below. An attacker needs an existing local foothold, for example through a phished account, malware or a shared multi-user system.
Affected
- Windows 10 Version 1607 (build 10.0.14393.0 before 10.0.14393.9612)
- Windows 10 Version 1809 (build 10.0.17763.0 before 10.0.17763.9376)
- Windows 10 Version 21H2 (build 10.0.19044.0 before 10.0.19044.7807)
- Windows 10 Version 22H2 (build 10.0.19045.0 before 10.0.19045.7807)
- Windows 11 Version 23H2 (build 10.0.22631.0 before 10.0.22631.7652)
- Windows 11 Version 24H2 (build 10.0.26100.0 before 10.0.26100.9711)
- Windows 11 Version 25H2 (build 10.0.26200.0 before 10.0.26200.9711)
- Windows 11 Version 26H2 (build 10.0.26300.0 before 10.0.26300.9711)
- Windows Server 2016, including Server Core (build 10.0.14393.0 before 10.0.14393.9612)
- Windows Server 2019, including Server Core (build 10.0.17763.0 before 10.0.17763.9376)
- Windows Server 2022 (build 10.0.20348.0 before 10.0.20348.5761)
- Windows Server 2025 (build 10.0.26100.0 before 10.0.26100.33650)
Fixed in
- Windows 10 Version 1607 and Windows Server 2016: 10.0.14393.9612 or later (KB number: unknown, check MSRC)
- Windows 10 Version 1809 and Windows Server 2019: 10.0.17763.9376 or later
- Windows 10 Version 21H2: 10.0.19044.7807 or later
- Windows 10 Version 22H2: 10.0.19045.7807 or later
- Windows 11 Version 23H2: 10.0.22631.7652 or later
- Windows 11 Version 24H2: 10.0.26100.9711 or later
- Windows 11 Version 25H2: 10.0.26200.9711 or later
- Windows 11 Version 26H2: 10.0.26300.9711 or later
- Windows Server 2022: 10.0.20348.5761 or later
- Windows Server 2025: 10.0.26100.33650 or later
Workaround
Unknown. No workaround is documented in the CVE record. Interim measure: restrict local logon to trusted users only.
Exploitation
- Not listed in CISA KEV.
- CISA SSVC: exploitation none, automatable no, technical impact total.
- EPSS: 0.00000 (VulDB).
- No public proof of concept found in the research; this does not prove that none exists.
Our recommendation
- Install the latest Microsoft cumulative update that contains the fix on all affected systems, prioritising multi-user machines and Remote Desktop or terminal servers.
- For Windows 10 1607 and Server 2016, confirm the KB number on the MSRC page.
- Check the Microsoft lifecycle page for Windows 10 1607 and Server 2016. If the systems are out of support or cannot be patched, plan a migration or check extended security update options.
- Restrict local logon to trusted users until patching is complete.
- Monitor for unusual privilege changes on endpoints and servers.
- Priority for SMEs: medium.
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows DWM Core Library
- 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, KB5126655, KB5126657, KB5126646, KB5127648, KB5126653
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Response Center: CVE-2026-88194 msrc.microsoft.com
- OpenCVE: CVE-2026-88194 app.opencve.io
- VulDB: CVE-2026-88194 vuldb.com
- Vulners: CVE-2026-88194 vulners.com
- Strix: CVE-2026-88194 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 2 Nov 2026, 01:08.
Original description (NVD)
Out-of-bounds read in Windows DWM Core Library 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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