---
id: "CVE-2026-96158"
page: "https://infrastack.ai/live/CVE-2026-96158"
kind: "vulnerability"
aliases: ["CVE-2026-96158"]
title: "Windows: ActiveX Installer Service flaw lets a local user gain higher privileges"
severity: "high"
cvss: 7.0
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["activex-installer-service", "infrastructure", "local-privilege-escalation", "windows"]
not_affected_if: ["no-local-untrusted-users"]
published_at: "2026-11-10T19:22:13+00:00"
first_seen_at: "2026-11-10T19:25:32+00:00"
updated_at: "2026-11-10T19:51:33+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-96158", "first_seen_at": "2026-11-10T19:25:32+00:00"}, {"source": "analyst", "url": "https://api.msrc.microsoft.com/sug/v2.0/en-US/vulnerability/CVE-2026-96158", "first_seen_at": "2026-11-10T19:51:33+00:00", "cites": ["https://api.msrc.microsoft.com/sug/v2.0/en-US/vulnerability/CVE-2026-96158"]}]
exploit_sources: []
---

# Windows: ActiveX Installer Service flaw lets a local user gain higher privileges

Link for people: https://infrastack.ai/live/CVE-2026-96158 (this .md is for agents)

Microsoft's November 2026 Patch Tuesday fixes an elevation of privilege in the ActiveX Installer Service (CWE-908 uninitialized resource, with a race condition). A local attacker with a low-privilege account who wins the race can gain SYSTEM. Microsoft rates it Important (CVSS 7.0), not publicly disclosed, not exploited, 'Exploitation Less Likely'.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

Microsoft's machine-readable advisory gives no KB or build numbers. Open the CVE-2026-96158 page in the MSRC Security Update Guide (it needs JavaScript) to get the KB for your Windows version, then compare it with the installed updates: Get-HotFix -Id KBxxxxxxx in PowerShell, or Settings > Windows Update > Update history. Whether the update is installed is the check. Version and KB numbers are unknown here.

## Timeline

- 2026-11-10T19:25:32+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-96158
- 2026-11-10T19:51:33+00:00 analyst https://api.msrc.microsoft.com/sug/v2.0/en-US/vulnerability/CVE-2026-96158 — MSRC API read: Important, EoP to SYSTEM, AC:H race, not exploited, not disclosed, customer action required. Build/KB list not in API; the SUG page is JS-only. Fix versions unknown. Nothing verified. X and search not used.

## Documents

- [advisory] MSRC: Microsoft ActiveX Installer Service Elevation of Privilege Vulnerability (CVE-2026-96158) https://api.msrc.microsoft.com/sug/v2.0/en-US/vulnerability/CVE-2026-96158

## From the sources

Use of uninitialized resource in Microsoft ActiveX Installer Service allows an authorized attacker to elevate privileges locally.

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_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_