---
id: "CVE-2026-96951"
kind: "vulnerability"
aliases: ["CVE-2026-96951"]
title: "Improper neutralization of special elements used in a command ('command injection') in Windows Shell allows an\u2026"
severity: "high"
cvss: 8.8
epss: null
exploited: true
status: "open"
category: "vendor"
products: [{"name": "Microsoft Windows", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "Windows 11 24H2", "fixed": ["10.0.26100.9711"], "affected": "< 10.0.26100.9711", "ecosystem": "vendor"}, {"name": "Windows 11 26H1", "fixed": ["10.0.28000.3231"], "affected": "< 10.0.28000.3231", "ecosystem": "vendor"}, {"name": "Windows 10 22H2", "fixed": ["10.0.19045.7807"], "affected": "< 10.0.19045.7807", "ecosystem": "vendor"}, {"name": "Windows Server 2025", "fixed": ["10.0.26100.33650"], "affected": "< 10.0.26100.33650", "ecosystem": "vendor"}, {"name": "microsoft outlook web", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows 10 1607", "fixed": ["10.0.14393.9612"], "affected": "< 10.0.14393.9612", "ecosystem": "vendor"}, {"name": "microsoft windows 10 1809", "fixed": ["10.0.17763.9376"], "affected": "< 10.0.17763.9376", "ecosystem": "vendor"}, {"name": "microsoft windows 10 21h2", "fixed": ["10.0.19044.7807"], "affected": "< 10.0.19044.7807", "ecosystem": "vendor"}, {"name": "microsoft windows 10 22h2", "fixed": ["10.0.19045.7807"], "affected": "< 10.0.19045.7807", "ecosystem": "vendor"}, {"name": "microsoft windows 11 23h2", "fixed": ["10.0.22631.7652"], "affected": "< 10.0.22631.7652", "ecosystem": "vendor"}, {"name": "microsoft windows 11 24h2", "fixed": ["10.0.26100.9711"], "affected": "< 10.0.26100.9711", "ecosystem": "vendor"}, {"name": "microsoft windows 11 25h2", "fixed": ["10.0.26200.9711"], "affected": "< 10.0.26200.9711", "ecosystem": "vendor"}, {"name": "microsoft windows 11 26h1", "fixed": ["10.0.28000.3231"], "affected": "< 10.0.28000.3231", "ecosystem": "vendor"}, {"name": "microsoft windows 11 26h2", "fixed": ["10.0.26300.9711"], "affected": "< 10.0.26300.9711", "ecosystem": "vendor"}, {"name": "microsoft windows server 2012", "fixed": [], "affected": "= r2", "ecosystem": "vendor"}, {"name": "microsoft windows server 2016", "fixed": ["10.0.14393.9612"], "affected": "< 10.0.14393.9612", "ecosystem": "vendor"}, {"name": "microsoft windows server 2019", "fixed": ["10.0.17763.9376"], "affected": "< 10.0.17763.9376", "ecosystem": "vendor"}, {"name": "microsoft windows server 2022", "fixed": ["10.0.20348.5761"], "affected": "< 10.0.20348.5761", "ecosystem": "vendor"}, {"name": "microsoft windows server 2025", "fixed": ["10.0.26100.33650"], "affected": "< 10.0.26100.33650", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["email-attachment", "exploited", "microsoft-windows-shell", "motw", "vendor", "windows"]
not_affected_if: ["patched-oct-2026", "unknown"]
published_at: "2026-10-13T00:00:00+00:00"
first_seen_at: "2026-10-23T19:11:50+00:00"
updated_at: "2026-10-23T23:44:52+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-96951", "first_seen_at": "2026-10-23T19:11:50+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-10-23T21:34:52+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-96951", "first_seen_at": "2026-10-23T23:44:52+00:00"}]
---

# Improper neutralization of special elements used in a command ('command injection') in Windows Shell allows an…

Windows Shell command injection (CWE-77) lets an attacker evade Mark of the Web (MOTW) protections. The user must open a crafted file or link, delivered by email, chat or a download. Microsoft rates it Important, CVSS 8.8, and reports exploitation detected. Fixed in the Oct 13 2026 Patch Tuesday updates. CISA lists it as exploited.

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

## Affected

- vendor:Microsoft Windows affected ? fixed ?
- vendor:Windows 11 24H2 affected < 10.0.26100.9711 fixed 10.0.26100.9711
- vendor:Windows 11 26H1 affected < 10.0.28000.3231 fixed 10.0.28000.3231
- vendor:Windows 10 22H2 affected < 10.0.19045.7807 fixed 10.0.19045.7807
- vendor:Windows Server 2025 affected < 10.0.26100.33650 fixed 10.0.26100.33650
- vendor:microsoft outlook web affected ? fixed ?
- vendor:microsoft windows 10 1607 affected < 10.0.14393.9612 fixed 10.0.14393.9612
- vendor:microsoft windows 10 1809 affected < 10.0.17763.9376 fixed 10.0.17763.9376
- vendor:microsoft windows 10 21h2 affected < 10.0.19044.7807 fixed 10.0.19044.7807
- vendor:microsoft windows 10 22h2 affected < 10.0.19045.7807 fixed 10.0.19045.7807
- vendor:microsoft windows 11 23h2 affected < 10.0.22631.7652 fixed 10.0.22631.7652
- vendor:microsoft windows 11 24h2 affected < 10.0.26100.9711 fixed 10.0.26100.9711
- vendor:microsoft windows 11 25h2 affected < 10.0.26200.9711 fixed 10.0.26200.9711
- vendor:microsoft windows 11 26h1 affected < 10.0.28000.3231 fixed 10.0.28000.3231
- vendor:microsoft windows 11 26h2 affected < 10.0.26300.9711 fixed 10.0.26300.9711
- vendor:microsoft windows server 2012 affected = r2 fixed ?
- vendor:microsoft windows server 2016 affected < 10.0.14393.9612 fixed 10.0.14393.9612
- vendor:microsoft windows server 2019 affected < 10.0.17763.9376 fixed 10.0.17763.9376
- vendor:microsoft windows server 2022 affected < 10.0.20348.5761 fixed 10.0.20348.5761
- vendor:microsoft windows server 2025 affected < 10.0.26100.33650 fixed 10.0.26100.33650

## How to check

Run winver or [System.Environment]::OSVersion and compare the build with the fixed builds. Win11 24H2: 10.0.26100.9711. Win11 26H1: 10.0.28000.3231. Win10 22H2: 10.0.19045.7807. Server 2025: 10.0.26100.33650. A build at or above these has the Oct 2026 update. Also run Get-HotFix for the KB listed on the MSRC page.

## Fix

Install the Oct 13 2026 cumulative update for your Windows version, using the builds above. KB numbers are on the MSRC page. No workaround is stated in what I read. Until patched, treat files from email or the web with caution and watch for attachments and scripts that run without a MOTW warning.

## Timeline

- 2026-10-23T19:11:50+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-96951
- 2026-10-23T21:34:52+00:00 analyst — Read MSRC page (released Oct 13 2026): Windows Shell MotW security feature bypass, CWE-77, CVSS 8.8, exploitation detected, not publicly disclosed. KB article numbers were cut off in the page text I got; the builds below are the ones I read. Server 2025 Server Core, Win11 26H1 and Win10 22H2 x64 rows were not seen. X posts were reposts, none saved.
- 2026-10-23T23:44:52+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-96951

## Documents

- [advisory] MSRC: Windows Shell Security Feature Bypass Vulnerability CVE-2026-96951 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-96951

## From the sources

Microsoft Windows Shell contains a command injection vulnerability that allows an unauthorized attacker to bypass a security feature over a network.

CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_