Windows 10 1607: Heap-based buffer overflow in Servicing Stack Updates
Summary
A heap-based buffer overflow in the Servicing Stack Updates component of Windows 10 Version 1607 and Windows Server 2016 allows an authorized local attacker to elevate privileges. The attacker needs local access and low-privileged credentials, and no user interaction is required. Microsoft rates the impact as high for confidentiality, integrity and availability (CVSS 3.1 7.8).
Affected
- Windows 10 Version 1607: 10.0.14393.0 to below 10.0.14393.9612
- Windows Server 2016: 10.0.14393.0 to below 10.0.14393.9612
Fixed in
- Windows 10 Version 1607 and Windows Server 2016: build 10.0.14393.9612 or later
- KB number: Unknown. Check the MSRC advisory for the update package.
Workaround
Unknown. No vendor workaround is documented; the fix is the security update.
Exploitation
- No public proof of concept or in-the-wild exploitation found at the time of research.
- MSRC exploit code maturity: Unproven (E:U).
- CISA SSVC: Exploitation none, Automatable no.
- Not listed in CISA KEV; EPSS below 1%.
Our recommendation
- Inventory all Windows 10 1607 and Windows Server 2016 systems and confirm their build numbers.
- Install the update with build 10.0.14393.9612 or later as soon as possible.
- Plan the upgrade of Windows 10 1607 systems, as this version is at or near end of support; verify the lifecycle status on Microsoft's website.
- Restrict local logon on shared or kiosk systems and monitor for privilege escalation.
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Servicing Stack Updates
- 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: CVE-2026-85318 msrc.microsoft.com
- Vulners MSCVE mirror: CVE-2026-85318 (affected ranges) vulners.com
- Vulners NVD entry: CVE-2026-85318 vulners.com
- OpenCVE: CVE-2026-85318 (CISA SSVC, KEV) app.opencve.io
- Strix: CVE-2026-85318 (third-party affected range) 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, 02:27.
Original description (NVD)
Heap-based buffer overflow in Servicing Stack Updates 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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