Microsoft Windows Installer: Use after free allows local privilege escalation
Summary
A use-after-free flaw in the Windows Installer component allows an authorized local user with low privileges to elevate their privileges. The attack requires local access and high complexity, and needs no user interaction. Successful exploitation could lead to full compromise of confidentiality, integrity and availability on the affected system.
Affected
- Windows 10 Version 1607: before 10.0.14393.9612
- Windows 10 Version 1809: before 10.0.17763.9376
- Windows 10 Version 21H2: before 10.0.19044.7807
- Windows 10 Version 22H2: Unknown (version range not confirmed)
- Windows 11 Version 23H2: before 10.0.22631.7652
- Windows 11 Version 24H2: before 10.0.26100.9711
- Windows 11 Version 25H2: before 10.0.26200.9711
- Windows 11 Version 26H1: before 10.0.28000.3231
- Windows 11 Version 26H2: before 10.0.26300.9711
- Windows Server 2012: before 6.2.9200.26434
- Windows Server 2012 R2: before 6.3.9600.23470
- Windows Server 2016: before 10.0.14393.9612
- Server Core installations of the above Windows Server 2012 and 2012 R2 are also affected
Fixed in
- Fixed builds correspond to the versions listed as 'before' above, from the CVE record. KB numbers: Unknown.
- Check the MSRC Security Update Guide for the authoritative list.
Workaround
Unknown.
Exploitation
- No known exploitation in the wild.
- No CISA KEV listing and no public proof of concept known at the time of writing.
- CISA SSVC: exploitation none, automatable no, technical impact total.
Our recommendation
- Install the security update for each affected Windows build as part of the normal patch cycle, with higher priority for shared systems, terminal servers and servers.
- Verify the fixed build and KB number on the MSRC page before rollout.
- Confirm that each host still receives security updates, especially older builds such as 1607 and 1809.
- Review which accounts have local logon on affected systems and restrict access where possible.
- Re-check exploitation status after the patch cycle.
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 less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5126835, KB5126836, KB5126868, KB5126651, KB5126657, KB5126655
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-96008 msrc.microsoft.com
- CVE.org CVE Record: CVE-2026-96008 www.cve.org
- Strix: CVE-2026-96008 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, 07:52.
Original description (NVD)
Use after free 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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