Microsoft Windows Kernel: Heap-based buffer overflow allows privilege escalation
Summary
A heap-based buffer overflow in the Windows kernel allows a local, unauthorized attacker to elevate privileges. The attack requires physical access to the device but no valid login. A successful attack would give the attacker full control over the affected host.
Affected
- Windows 10 Version 1607 (before 10.0.14393.9688)
- Windows 10 Version 1809 (before 10.0.17763.9487)
- Windows 10 Version 21H2 (before 10.0.19044.7846)
- Windows 10 Version 22H2 (before 10.0.19045.7846, per the CNA record; the entry is truncated, so verify)
- Windows 11 Version 23H2 (before 10.0.22631.7711)
- Windows 11 Version 24H2 (before 10.0.26100.9974)
- Windows 11 Version 25H2 (before 10.0.26200.9974)
- Windows 11 Version 26H1 (before 10.0.28000.3501)
- Windows 11 Version 26H2 (before 10.0.26300.9974)
- Windows Server 2016, including Server Core (before 10.0.14393.9688)
- Windows Server 2019, including Server Core (before 10.0.17763.9487)
- Windows Server 2022 (before 10.0.20348.5870)
Fixed in
- Install the Microsoft security update for November 2026 on each affected build.
- Fixed builds as listed in the CNA record: see the affected list above.
- Exact KB numbers per version: check the MSRC advisory.
Workaround
Unknown. No vendor workaround was found; the security update is the primary remedy.
Exploitation
- No confirmed exploitation at publication.
- No public proof of concept found.
- The CVSS temporal metric Exploit Code Maturity is 'unproven' (E:U).
- CISA SSVC: exploitation none, automatable no, technical impact total.
Our recommendation
- Install the November 2026 Windows security update on all affected hosts, prioritising laptops, mobile devices and shared or public workstations.
- Confirm that all hosts run a supported Windows build; older builds such as 1607 and 1809 may be out of support.
- Enable BitLocker or device encryption, use a BIOS/UEFI password and Secure Boot, and disable unused USB or external boot options to reduce physical attack risk.
- Restrict physical access to unattended and public-facing systems.
- Monitor for signs of local privilege escalation.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows Kernel
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation unlikely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131291, KB5131085, KB5131096, KB5131090, KB5131087, KB5132061
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- CVE.org CNA record (Microsoft) www.cve.org
- MSRC Security Update Guide msrc.microsoft.com
- Rapid7 Patch Tuesday review, November 2026 www.rapid7.com
- Strix.ai (unverified version list) www.strix.ai
- Senserva KB 5131096 (update contents) senserva.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 11 Nov 2026, 10:36.
Original description (NVD)
Heap-based buffer overflow in Windows Kernel allows an unauthorized attacker to elevate privileges with a physical attack.
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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