Microsoft Windows Installer: Elevation of privilege via incorrect authorization
Summary
Incorrect authorization in Windows Installer allows an authenticated local attacker with low privileges to elevate privileges on the affected system. The CVSS vector indicates high impact on confidentiality, integrity and availability if exploited. Exploitation requires local access and a foothold such as a standard user account, a compromised service account or a malicious insider.
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
- 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 before 10.0.14393.9688
- Windows Server 2019 before 10.0.17763.9487
- Windows Server 2022 before 10.0.20348.5870
- Note: the exact product-to-build mapping is not fully verified against the MSRC table.
Fixed in
- Microsoft Security Update released on November 10, 2026 (Patch Tuesday)
- Fixed builds: see the affected list above, confirm on the MSRC page
- KB mapping: unverified, confirm on the MSRC page before deployment
Workaround
- No workaround or mitigation found in the sources.
- Patching is the primary remedy.
Exploitation
- Microsoft exploitability assessment: More Likely.
- CVSS temporal vector indicates exploit code maturity Unproven; no public proof of concept found.
- Reports say one bug in the November 2026 release was exploited in the wild, but it is not named and not confirmed to be this CVE.
- CISA SSVC: exploitation none, automatable no, technical impact total.
Our recommendation
- Apply the November 10, 2026 Windows security update to all affected systems and confirm the KB and build numbers on the MSRC page.
- Prioritize multi-user systems, terminal servers and workstations where users are not local administrators.
- Monitor for public exploit code and a CISA KEV listing.
- Review NVD for updated CVSS and CWE data once analysis is complete.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows Installer
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation more likely
- 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
- Microsoft Security Update Guide msrc.microsoft.com
- CVE Record (CVE.org) www.cve.org
- Strix AI CVE details www.strix.ai
- Tenable November 2026 Patch Tuesday www.tenable.com
- Trinetri Patch Tuesday November 2026 trinetriops.com
- Talos Microsoft Patch Tuesday November 2026 blog.talosintelligence.com
- Qualys Patch Tuesday November 2026 review blog.qualys.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, 03:44.
Original description (NVD)
Incorrect authorization in Windows Installer 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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