---
id: CVE-2026-66804
title: Microsoft Windows Cross Device Service Elevation of Privilege Vulnerability
summary: >-
  Improper access control in Windows Cross Device Service allows an authorized
  attacker to elevate privileges locally.
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C'
cvssSource: cna
cwe:
  - CWE-284
vendor: Microsoft
product: Windows 10 Version 22H2
affected:
  - windows_10_version_22h2 >= 10.0.19045.0 < 10.0.19045.7663
  - windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.9168
  - windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.9168
  - windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.2704
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-08-12T15:47:52.685838Z'
exploitAvailable: true
published: '2026-08-11'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T13:45:48.646Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-66804'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66804'
    label: >-
      Microsoft Windows Cross Device Service Elevation of Privilege
      Vulnerability
tags:
  - cve.org
  - exploit-available
epss: 0.00298
epssPercentile: 0.1996
exploits:
  github: 4
  githubRepos:
    - 'https://github.com/Rat5ak/CVE-2026-66804-CrossDevice-Service-EoP'
    - 'https://github.com/DavidCarliez/CVE-2026-66804-CrossDevice-LPE'
    - 'https://github.com/ZeroDayVPN/CVE-2026-66804-CrossDevice-Service-EoP'
  checkedAt: '2026-09-25T08:21:08.185Z'
ingestedAt: '2026-09-08T18:07:34.894Z'
---

## Overview

Improper access control in Windows Cross Device Service allows an authorized attacker to elevate privileges locally.

## Affected

- `windows_10_version_22h2 >= 10.0.19045.0 < 10.0.19045.7663`
- `windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.9168`
- `windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.9168`
- `windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.2704`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.