Windows 10 1607: Use-after-free in kernel allows local privilege escalation
Summary
A use-after-free flaw (CWE-416) in the Windows kernel of Windows 10 Version 1607 allows an attacker with a local, low-privileged account to elevate privileges. The attack is rated as high complexity and requires no user interaction, and successful exploitation has high impact on confidentiality, integrity and availability. The flaw is not directly exploitable from the internet, so the risk is mainly on shared or legacy systems where an attacker already has local access. Windows 10 Enterprise LTSB 2016 reached the end of updates on 13 October 2026.
Affected
- Windows 10 Version 1607: builds 10.0.14393.0 before 10.0.14393.9612
- Windows Server 2016: builds 10.0.14393.0 before 10.0.14393.9612 (per CNA record, verify on MSRC)
- The CNA record also lists other Windows 10, Windows 11 and Windows Server versions
Fixed in
- October 2026 cumulative update (KB5126868) for Windows 10 1607, build 10.0.14393.9612 or later (likely, not confirmed for this CVE)
- Verify the fixed build for Windows Server 2016 on the MSRC update guide
Workaround
Unknown. No vendor workaround was found in the sources reviewed.
- Restrict local logon and apply least privilege to reduce the risk
Exploitation
- No known exploitation in the sources reviewed
- Not listed in CISA KEV; SSVC assessment: exploitation none, not automatable
- EPSS at 0.27% according to a third-party tracker
- No public proof of concept found for this CVE
Our recommendation
- Inventory all Windows 10 1607 (LTSB 2016) and Windows Server 2016 hosts
- Confirm the October 2026 cumulative update is installed
- Plan migration off LTSB 2016 now; evaluate ESU only as a time-limited bridge
- Restrict local accounts and monitor for privilege escalation on legacy hosts
- Re-check the MSRC page and CISA KEV for changes
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows Kernel
- 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
- MSRC Security Update Guide entry msrc.microsoft.com
- NVD mirror on Vulners vulners.com
- CNA record on Vulners vulners.com
- OpenCVE record app.opencve.io
- Microsoft release health: Windows 10 1607 and Server 2016 learn.microsoft.com
- 4sysops: LTSB 2016 end of support and ESU 4sysops.com
- GitHub vulnerability tracker entry github.com
- Wikipedia: Windows Server 2016 en.wikipedia.org
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 4 Nov 2026, 09:08.
Original description (NVD)
Use after free in Windows Kernel 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.
Affected? We can help.
We check whether your systems are affected, install updates and close the gap – continuously with the System Health Checker if you wish.