---
id: CVE-2026-0390
title: UEFI Secure Boot Security Feature Bypass Vulnerability
summary: >-
  Reliance on untrusted inputs in a security decision in Windows Boot Loader
  allows an authorized attacker to bypass a security feature locally.
severity: medium
cvss: 6.7
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C'
cvssSource: cna
cwe:
  - CWE-807
vendor: Microsoft
product: Windows 10 Version 1607
affected:
  - windows_10_version_1607 >= 10.0.14393.0 < 10.0.14393.9060
  - windows_10_version_1809 >= 10.0.17763.0 < 10.0.17763.8644
  - windows_10_version_21h2 >= 10.0.19044.0 < 10.0.19044.7184
  - windows_10_version_22h2 >= 10.0.19045.0 < 10.0.19045.7184
  - windows_server_2016 >= 10.0.14393.0 < 10.0.14393.9060
  - >-
    windows_server_2016_server_core_installation >= 10.0.14393.0 <
    10.0.14393.9060
  - windows_server_2019 >= 10.0.17763.0 < 10.0.17763.8644
  - >-
    windows_server_2019_server_core_installation >= 10.0.17763.0 <
    10.0.17763.8644
  - windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5020
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-04-15T03:57:24.351150Z'
published: '2026-04-14'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T17:25:18.702Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-0390'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-0390'
    label: UEFI Secure Boot Security Feature Bypass Vulnerability
tags:
  - cve.org
epss: 0.00318
epssPercentile: 0.22039
ingestedAt: '2026-09-25T18:14:20.448Z'
---

## Overview

Reliance on untrusted inputs in a security decision in Windows Boot Loader allows an authorized attacker to bypass a security feature locally.

## Affected

- `windows_10_version_1607 >= 10.0.14393.0 < 10.0.14393.9060`
- `windows_10_version_1809 >= 10.0.17763.0 < 10.0.17763.8644`
- `windows_10_version_21h2 >= 10.0.19044.0 < 10.0.19044.7184`
- `windows_10_version_22h2 >= 10.0.19045.0 < 10.0.19045.7184`
- `windows_server_2016 >= 10.0.14393.0 < 10.0.14393.9060`
- `windows_server_2016_server_core_installation >= 10.0.14393.0 < 10.0.14393.9060`
- `windows_server_2019 >= 10.0.17763.0 < 10.0.17763.8644`
- `windows_server_2019_server_core_installation >= 10.0.17763.0 < 10.0.17763.8644`
- `windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5020`

## Remediation

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