Microsoft Windows DWM Core Library: Out-of-bounds read leads to privilege escalation
Summary
An out-of-bounds read in the Windows DWM Core Library (Desktop Window Manager) allows a local attacker with low privileges to elevate privileges. Successful exploitation could give the attacker full control over confidentiality, integrity and availability of the affected system. The attacker needs a local account on the system; the flaw cannot be exploited remotely without prior access.
Affected
- Windows 10 Version 1809 and Windows Server 2019 (including Server Core): builds before 10.0.17763.9376
- Windows 10 Version 21H2: builds before 10.0.19044.7807
- Windows 10 Version 22H2: builds before 10.0.19045.7807
- Windows 11 Version 23H2: builds before 10.0.22631.7652
- Windows 11 Version 24H2: builds before 10.0.26100.9711
- Windows 11 Version 25H2 and 26H2: builds before 10.0.26200.9711 and 10.0.26300.9711
- Windows Server 2022: builds before 10.0.20348.5761
- Windows Server 2025 (including Server Core): builds before 10.0.26100.33650
- Note: sources differ on the fixed build for some 26100 products; verify against the MSRC advisory.
Fixed in
Install the Windows security cumulative update from October 2026 or later that addresses CVE-2026-88180, as listed in the MSRC Security Update Guide. The sources mention KB5126651 for Windows 10 1809 and Server 2019; verify the KB number on MSRC.
Workaround
Unknown. No vendor workaround was found in the sources. Install the cumulative update as the remedy.
Exploitation
- CISA SSVC: exploitation none, automatable no, technical impact total.
- Microsoft temporal vector: exploit code maturity unproven, report confidence confirmed.
- EPSS: 0.00245.
- No public proof of concept, exploitation in the wild or CISA KEV listing was found in limited searches.
Our recommendation
- Deploy the October 2026 Windows cumulative update on all affected systems, prioritising multi-user systems, terminal servers and shared workstations.
- Verify the exact fixed build per product in the MSRC advisory before rollout.
- Until patched, limit local logon to trusted users and avoid shared multi-user sessions on servers.
- Monitor for unusual local processes and privilege changes.
- Check the support status of your Windows edition before planning upgrades.
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)
- KB5127648, KB5126651, KB5126655, KB5126657, KB5126646, KB5126653
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-88180 msrc.microsoft.com
- OpenCVE: CVE-2026-88180 app.opencve.io
- Vulners CVE list: CVE-2026-88180 vulners.com
- Vulners VulnRichment: CVE-2026-88180 vulners.com
- Qualys: Microsoft Patch Tuesday October 2026 blog.qualys.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, 01:13.
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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