Microsoft Windows Search: Heap-based buffer overflow enables local privilege escalation
Summary
A heap-based buffer overflow in the Microsoft Windows Search Component allows an authorized local attacker to elevate privileges. The CNA record lists several Windows 10, Windows 11 and Windows Server versions as affected, including Windows 10 Version 1607 and Windows Server 2016. An attacker needs a local account with low privileges and could gain SYSTEM rights, with high impact on confidentiality, integrity and availability. CISA SSVC data lists exploitation as none and the vulnerability as not automatable.
Affected
- Windows 10 Version 1607: 10.0.14393.0 before 10.0.14393.9612
- Windows Server 2016: 10.0.14393.0 before 10.0.14393.9612
- Other Windows 10, Windows 11 and Windows Server versions are listed in the CNA record and the MSRC advisory.
Fixed in
- Windows 10 Version 1607 and Windows Server 2016: build 10.0.14393.9612 or later
- Install the October 2026 security update released by Microsoft and verify the build against the MSRC table.
- Restart the system or the WSearch service after installation.
Workaround
None known beyond patching.
Exploitation
- No public proof-of-concept or in-the-wild exploitation found in the sources; treat as unknown.
- Not listed in CISA KEV.
- CISA SSVC: exploitation none, not automatable, total technical impact.
- EPSS: 0.00353 (as reported by Vulners).
Our recommendation
- Identify Windows 10 1607 and Windows Server 2016 systems and check whether they are still in service.
- Install the security update providing build 10.0.14393.9612 or later and verify it on the MSRC page.
- Restart affected systems after patching so the changes take effect.
- Check Microsoft's lifecycle page for Windows 10 1607 support status and plan replacement of unsupported systems.
- Restrict local accounts and monitor for suspicious privilege escalation on user PCs and servers.
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Microsoft Windows Search Component
- 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 Update Guide (CVE-2026-83829) msrc.microsoft.com
- OpenCVE: CVE-2026-83829 app.opencve.io
- Vulners NVD mirror: CVE-2026-83829 vulners.com
- Strix: CVE-2026-83829 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, 02:56.
Original description (NVD)
Heap-based buffer overflow in Microsoft Windows Search Component 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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