Microsoft Windows Search: Heap-based buffer overflow allows local privilege escalation
Summary
The Windows Search Component of several Windows 10, Windows 11 and Windows Server releases contains a heap-based buffer overflow. An authorized local user with low privileges can exploit it to elevate privileges, with high impact on confidentiality, integrity and availability. Local access is required, so the risk mainly arises after a phishing or malware compromise. Public exploit code is not known from the sources reviewed.
Affected
- Windows 10 Version 1607 (10.0.14393.0 before 10.0.14393.9612)
- Windows 10 Version 1809 (10.0.17763.0 before 10.0.17763.9376)
- Windows 10 Version 21H2 (10.0.19044.0 before 10.0.19044.7807)
- Windows 10 Version 22H2 (10.0.19045.0 before 10.0.19045.7807)
- Windows 11 Version 23H2 (10.0.22631.0 before 10.0.22631.7652)
- Windows 11 Version 24H2 (10.0.26100.0 before 10.0.26100.9711)
- Windows 11 Version 25H2 (10.0.26200.0 before 10.0.26200.9711)
- Windows 11 Version 26H1 (10.0.28000.0 before 10.0.28000.3231)
- Windows 11 Version 26H2 (10.0.26300.0 before 10.0.26300.9711)
- Windows Server 2012 and Server Core installation (6.2.9200.0 before 6.2.9200.26434)
- Windows Server 2012 R2 and Server Core installation (6.3.9600.0 before 6.3.9600.23470)
- Windows Server 2016 (10.0.14393.0 before 10.0.14393.9612)
Fixed in
- Windows 10 Version 1607: 10.0.14393.9612
- Windows 10 Version 1809: 10.0.17763.9376
- Windows 10 Version 21H2: 10.0.19044.7807
- Windows 10 Version 22H2: 10.0.19045.7807
- Windows 11 Version 23H2: 10.0.22631.7652
- Windows 11 Version 24H2: 10.0.26100.9711
- Windows 11 Version 25H2: 10.0.26200.9711
- Windows 11 Version 26H1: 10.0.28000.3231
- Windows 11 Version 26H2: 10.0.26300.9711
- Windows Server 2012: 6.2.9200.26434
- Windows Server 2012 R2: 6.3.9600.23470
- Windows Server 2016: 10.0.14393.9612
The fixed builds are taken from the CNA data and should be confirmed in the Microsoft Security Update Guide.
Workaround
Unknown. No vendor workaround was found. Installing the security update is the primary measure.
Exploitation
- Not listed in the CISA Known Exploited Vulnerabilities catalog.
- CISA SSVC: exploitation none, automatable no, technical impact total.
- EPSS score 0.00361.
- No public proof of concept or in-the-wild exploitation found in the sources reviewed.
Our recommendation
- Install the Microsoft security update for all affected Windows versions, prioritising systems with many users or shared logins.
- Check whether Windows 10 Version 1607 or Windows Server 2016 is still in use and plan an upgrade, since these older releases may no longer receive fixes.
- Verify the fixed build numbers in the Microsoft Security Update Guide before rollout.
- Monitor for suspicious local privilege escalation activity on endpoints 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)
- 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-2026-83850 msrc.microsoft.com
- CVE List (CNA data): CVE-2026-83850 vulners.com
- NVD record: CVE-2026-83850 vulners.com
- OpenCVE: CVE-2026-83850 app.opencve.io
- Strix: CVE-2026-83850 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, 02:52.
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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