Windows Installer: Information disclosure through uninitialized resource
Summary
Windows Installer, the Windows service that installs and maintains MSI packages, uses an uninitialized resource. An unauthorized attacker who can reach the affected system over the network may be able to read sensitive information. The impact is limited to confidentiality, and the required conditions and user interaction are not fully confirmed by the vendor yet.
Affected
- Windows 10 Version 1607, Windows Server 2016 (including Server Core): 10.0.14393.0 to before 10.0.14393.9688
- Windows 10 Version 1809, Windows Server 2019 (including Server Core): 10.0.17763.0 to before 10.0.17763.9487
- Windows 10 Version 21H2: 10.0.19044.0 to before 10.0.19044.7846
- Windows 10 Version 22H2: 10.0.19045.0 to before 10.0.19045.7846
- Windows 11 Version 23H2: 10.0.22631.0 to before 10.0.22631.7711
- Windows 11 Version 24H2: 10.0.26100.0 to before 10.0.26100.9974
- Windows 11 Version 25H2: 10.0.26200.0 to before 10.0.26200.9974
- Windows 11 Version 26H1: 10.0.28000.0 to before 10.0.28000.3501
- Windows 11 Version 26H2: 10.0.26300.0 to before 10.0.26300.9974
- Windows Server 2022: 10.0.20348.0 to before 10.0.20348.5870
- The product list differs between sources and has not been verified against the MSRC advisory.
Fixed in
- According to the CNA record, fixed builds are: 10.0.14393.9688 (1607, Server 2016), 10.0.17763.9487 (1809, Server 2019), 10.0.19044.7846 (21H2), 10.0.19045.7846 (22H2), 10.0.22631.7711 (23H2), 10.0.26100.9974 (24H2), 10.0.26200.9974 (25H2), 10.0.28000.3501 (26H1), 10.0.26300.9974 (26H2), 10.0.20348.5870 (Server 2022).
- Secondary sources associate the fix with the November 2026 Windows security update. KB numbers and builds still need to be confirmed in the Microsoft Update Catalog.
Workaround
Unknown.
- No vendor-documented workaround was found.
- Restrict network access to affected hosts and limit installation of untrusted MSI packages until patched.
Exploitation
- No evidence of exploitation in the wild.
- No public proof of concept found.
- Not listed in CISA KEV. EPSS score not found.
- CISA SSVC: exploitation none, not automatable, partial technical impact.
Our recommendation
- Check the asset inventory for affected Windows 10, Windows 11 and Windows Server versions.
- Apply the November 2026 cumulative updates in the normal patch cycle, starting with internet-facing and multi-user systems such as terminal servers and file servers.
- Verify the affected builds and fixes on the MSRC advisory before deployment.
- Monitor NVD, CISA KEV and EPSS for changes.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Information disclosure – Windows Installer
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131085, KB5131090, KB5131096, KB5131080, KB5131077, KB5132061
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Response Center advisory msrc.microsoft.com
- CVE.org CVE record (CNA: Microsoft) www.cve.org
- Senserva KB 5132059 (secondary) senserva.com
- Senserva KB 5131085 (secondary) senserva.com
- Senserva KB 5132061 (secondary) senserva.com
- Strix CVE-2026-119887 (aggregator, unverified) 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 11 Nov 2026, 12:08.
Original description (NVD)
Use of uninitialized resource in Windows Installer allows an unauthorized attacker to disclose information over a network.
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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