---
id: CVE-2026-20804
title: >-
  Incorrect privilege assignment in Windows Hello allows an unauthorized
  attacker to perform tampering locally.
summary: >-
  Incorrect privilege assignment in Windows Hello allows an unauthorized
  attacker to perform tampering locally.
severity: high
cvss: 7.7
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-266
vendor: microsoft
product: windows_10_1607
affected:
  - windows_10_1607 < 10.0.14393.8783
  - windows_10_1809 < 10.0.17763.8276
  - windows_10_21h2 < 10.0.19044.6809
  - windows_10_22h2 < 10.0.19045.6809
  - windows_11_23h2 < 10.0.22631.6491
  - windows_11_24h2 < 10.0.26100.7623
  - windows_11_25h2 < 10.0.26200.7623
  - windows_server_2016 < 10.0.14393.8783
  - windows_server_2019 < 10.0.17763.8276
  - windows_server_2022 < 10.0.20348.4648
  - windows_server_2022_23h2 < 10.0.25398.2092
  - windows_server_2025 < 10.0.26100.32230
patched:
  - windows_10_1607 10.0.14393.8783
  - windows_10_1809 10.0.17763.8276
  - windows_10_21h2 10.0.19044.6809
  - windows_10_22h2 10.0.19045.6809
  - windows_11_23h2 10.0.22631.6491
  - windows_11_24h2 10.0.26100.7623
  - windows_11_25h2 10.0.26200.7623
  - windows_server_2016 10.0.14393.8783
  - windows_server_2019 10.0.17763.8276
  - windows_server_2022 10.0.20348.4648
  - windows_server_2022_23h2 10.0.25398.2092
  - windows_server_2025 10.0.26100.32230
published: '2026-01-13'
updated: '2026-07-30'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-20804'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20804'
    label: secure@microsoft.com
tags:
  - nvd
epss: 0.00508
epssPercentile: 0.42425
ingestedAt: '2026-07-31T06:58:51.116Z'
---

## Overview

Incorrect privilege assignment in Windows Hello allows an unauthorized attacker to perform tampering locally.

## Affected

- `windows_10_1607 < 10.0.14393.8783`
- `windows_10_1809 < 10.0.17763.8276`
- `windows_10_21h2 < 10.0.19044.6809`
- `windows_10_22h2 < 10.0.19045.6809`
- `windows_11_23h2 < 10.0.22631.6491`
- `windows_11_24h2 < 10.0.26100.7623`
- `windows_11_25h2 < 10.0.26200.7623`
- `windows_server_2016 < 10.0.14393.8783`
- `windows_server_2019 < 10.0.17763.8276`
- `windows_server_2022 < 10.0.20348.4648`
- `windows_server_2022_23h2 < 10.0.25398.2092`
- `windows_server_2025 < 10.0.26100.32230`

## Remediation

Upgrade past the affected range:

- `windows_10_1607 10.0.14393.8783`
- `windows_10_1809 10.0.17763.8276`
- `windows_10_21h2 10.0.19044.6809`
- `windows_10_22h2 10.0.19045.6809`
- `windows_11_23h2 10.0.22631.6491`
- `windows_11_24h2 10.0.26100.7623`
- `windows_11_25h2 10.0.26200.7623`
- `windows_server_2016 10.0.14393.8783`
- `windows_server_2019 10.0.17763.8276`
- `windows_server_2022 10.0.20348.4648`
- `windows_server_2022_23h2 10.0.25398.2092`
- `windows_server_2025 10.0.26100.32230`