Windows Installer: Elevation of privilege via use-after-free
Summary
A use-after-free flaw in Windows Installer allows an authorized local attacker to elevate privileges on affected Windows 10, Windows 11 and Windows Server systems. The attacker needs local access and an existing low-privileged account, and the attack complexity is high. CVSS 3.1 base score is 7.0 (HIGH); the CVE record is still awaiting NVD analysis.
Affected
- Windows 10 Version 1607 (builds before 10.0.14393.9688)
- Windows 10 Version 1809 (builds before 10.0.17763.9487)
- Windows 10 Version 21H2 (builds before 10.0.19044.7846)
- Windows 10 Version 22H2 (builds before 10.0.19045.7846, unconfirmed)
- Windows 11 Version 23H2 (builds before 10.0.22631.7711, unconfirmed)
- Windows 11 Version 24H2, 25H2, 26H1 and 26H2 (fixed builds listed in the CVE record, unverified)
- Windows Server 2016, 2019 and 2022 (including Server Core, fixed builds listed in the CVE record, unverified)
- Full list: Microsoft Security Response Center advisory
Fixed in
- Install the November 2026 Windows security update for each affected branch.
- Minimum fixed builds per the CVE record: 10.0.14393.9688 (1607), 10.0.17763.9487 (1809), 10.0.19044.7846 (21H2).
- Exact KB numbers: see the MSRC advisory (not verified).
Workaround
- Unknown. No workaround is documented; patching is the remedy.
Exploitation
- Unknown. No source confirms in-the-wild exploitation or public proof-of-concept code.
- CISA SSVC assessment: exploitation none, not automatable, total technical impact.
Our recommendation
- Deploy the November 2026 cumulative update on all listed Windows 10, Windows 11 and Windows Server systems, prioritising machines with local user accounts and shared administrator rights.
- Reduce local administrator rights where possible.
- Check whether the MSRC page or CISA KEV marks the CVE as exploited; if so, raise the priority.
- Identify systems on unsupported branches (Windows 10 1607 and 1809) and plan an upgrade or ESU enrolment.
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)
- KB5131291, KB5131085, KB5131096, KB5131090, KB5131087, KB5132061
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- CVE Record CVE-2026-96035 www.cve.org
- Microsoft Security Update Guide CVE-2026-96035 msrc.microsoft.com
- Strix AI CVE-2026-96035 www.strix.ai
- Rapid7 Patch Tuesday November 2026 www.rapid7.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, 07:47.
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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