CVE-2026-45654 - Vulnerability Details

- Secure Boot Security Feature Bypass Vulnerability

Description

Improper access control in Windows Secure Boot allows an authorized attacker to bypass a security feature locally.

Published: 2026-06-09

Score: 7.9 High

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Impact

Improper access control in Windows Secure Boot allows an authorized local attacker to bypass the Secure Boot enforcement, enabling the installation or execution of unsigned firmware or boot components.

Affected Systems

Affected workloads are Microsoft Windows 11 versions 24H2, 25H2, and 26H1 on both ARM64 and x64 architectures, along with Windows Server 2025, including Server Core installations.

Risk and Exploitability

The CVSS score is 7.9 and the EPSS score is <1%. The vulnerability is not listed in the CISA KEV catalog. The attack vector is local and requires authenticated access to the system. The potential impact is limited to the ability to bypass Secure Boot enforcement, which could allow the installation of unsigned code or firmware during the boot process.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Microsoft

Windows 11 Version 24H2

affected

Version	Status	Constraints
`10.0.26100.0`	affected	< 10.0.26100.8655

Microsoft

Windows 11 Version 25H2

affected

Version	Status	Constraints
`10.0.26200.0`	affected	< 10.0.26200.8655

Microsoft

Windows 11 version 26H1

affected

Version	Status	Constraints
`10.0.28000.0`	affected	< 10.0.28000.2269

Microsoft

Windows Server 2025

affected

Version	Status	Constraints
`10.0.26100.0`	affected	< 10.0.26100.32995

Microsoft

Windows Server 2025 (Server Core installation)

affected

Version	Status	Constraints
`10.0.26100.0`	affected	< 10.0.26100.32995

Configuration 1 [-]

OR	cpe:2.3:o:microsoft:windows_11_24h2:::::::arm64:*
	cpe:2.3:o:microsoft:windows_11_24h2:::::::x64:*
	cpe:2.3:o:microsoft:windows_11_25h2:::::::arm64:*
	cpe:2.3:o:microsoft:windows_11_25h2:::::::x64:*
	cpe:2.3:o:microsoft:windows_11_26h1:::::::arm64:*
	cpe:2.3:o:microsoft:windows_11_26h1:::::::x64:*
	cpe:2.3:o:microsoft:windows_server_2025:::::::x64:*

No data.

Vendor Product Confidence Versions

Microsoft

Windows 11 24h2

86%

Version	Status	Scheme	Platform
`[10.0.26100.0,10.0.26100.8655)`	affected	generic	['arm64-based_systems', 'x64-based_systems']

Microsoft

Windows 11 25h2

86%

Version	Status	Scheme	Platform
`[10.0.26200.0,10.0.26200.8655)`	affected	generic	['arm64-based_systems', 'x64-based_systems']

Microsoft

Windows 11 26h1

86%

Version	Status	Scheme	Platform
`[10.0.28000.0,10.0.28000.2269)`	affected	generic	['arm64-based_systems']

Microsoft

Windows 11 26h1

86%

Version	Status	Scheme	Platform
`[1.0.0,10.0.28000.2269)`	affected	generic	['x64-based_systems']

Microsoft

Windows Server 2025

100%

Version	Status	Scheme	Platform
`[10.0.26100.0,10.0.26100.32995)`	affected	generic	['x64-based_systems']

Microsoft

Windows Server 2025 (server Core Installation)

100%

Version	Status	Scheme	Platform
`[10.0.26100.0,10.0.26100.32995)`	affected	generic	['x64-based_systems']

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Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

Install the Microsoft security update for CVE‑2026‑45654 as documented in the Microsoft Security Response Center update guide to patch the improper access control issue.
Configure UEFI Secure Boot so that only privileged administrators can modify boot configuration, ensuring that all changes to Secure Boot settings require explicit administrative approval.
Enable UEFI firmware event logging and regularly review the logs for any unauthorized changes to boot configuration or firmware signatures.

Generated by OpenCVE AI on August 2, 2026 at 01:49 UTC.

Tracking

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Advisories

No advisories yet.

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required High

Scope Changed

Confidentiality Impact High

Integrity Impact High

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00309.

Exploitation none

Automatable no

Technical Impact total

References

Link	Providers
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45654

History

Wed, 08 Jul 2026 23:30:00 +0000

Type	Values Removed	Values Added
Description	Protection mechanism failure in Windows Secure Boot allows an authorized attacker to bypass a security feature locally.	Improper access control in Windows Secure Boot allows an authorized attacker to bypass a security feature locally.

Mon, 15 Jun 2026 20:30:00 +0000

Type	Values Removed	Values Added
CPEs	cpe:2.3:o:microsoft:windows_11_26H1:::::::arm64:*

Thu, 11 Jun 2026 19:00:00 +0000

Type	Values Removed	Values Added
CPEs		cpe:2.3:o:microsoft:windows_11_24h2:::::::arm64:* cpe:2.3:o:microsoft:windows_11_24h2:::::::x64:* cpe:2.3:o:microsoft:windows_11_25h2:::::::arm64:* cpe:2.3:o:microsoft:windows_11_25h2:::::::x64:* cpe:2.3:o:microsoft:windows_11_26h1:::::::arm64:* cpe:2.3:o:microsoft:windows_11_26h1:::::::x64:* cpe:2.3:o:microsoft:windows_server_2025:::::::x64:*

Wed, 10 Jun 2026 11:30:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}`

Wed, 10 Jun 2026 11:15:00 +0000

Type	Values Removed	Values Added
First Time appeared		Microsoft windows 11 24h2 Microsoft windows 11 25h2 Microsoft windows 11 26h1 Microsoft windows Server 2025 (server Core Installation)
Vendors & Products		Microsoft windows 11 24h2 Microsoft windows 11 25h2 Microsoft windows 11 26h1 Microsoft windows Server 2025 (server Core Installation)

Tue, 09 Jun 2026 17:15:00 +0000

Type	Values Removed	Values Added
Description		Protection mechanism failure in Windows Secure Boot allows an authorized attacker to bypass a security feature locally.
Title		Secure Boot Security Feature Bypass Vulnerability
First Time appeared		Microsoft Microsoft windows 11 24h2 Microsoft windows 11 25h2 Microsoft windows 11 26h1 Microsoft windows Server 2025
Weaknesses		CWE-284
CPEs		cpe:2.3:o:microsoft:windows_11_24H2:::::::arm64:* cpe:2.3:o:microsoft:windows_11_25H2:::::::arm64:* cpe:2.3:o:microsoft:windows_11_26H1:::::::arm64:* cpe:2.3:o:microsoft:windows_11_26H1:::::::x64:* cpe:2.3:o:microsoft:windows_server_2025::::::::
Vendors & Products		Microsoft Microsoft windows 11 24h2 Microsoft windows 11 25h2 Microsoft windows 11 26h1 Microsoft windows Server 2025
References		https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45654
Metrics		cvssV3_1 `{'score': 7.9, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N/E:U/RL:O/RC:C'}`

Subscriptions

Microsoft Windows 11 24h2 Windows 11 24h2 Windows 11 25h2 Windows 11 25h2 Windows 11 26h1 Windows 11 26h1 Windows Server 2025 Windows Server 2025 (server Core Installation)

MITRE

Status: PUBLISHED

Assigner: microsoft

Published: 2026-06-09T17:05:43.972Z

Updated: 2026-07-28T22:19:32.990Z

Reserved: 2026-05-12T20:33:35.157Z

Link: CVE-2026-45654

Vulnrichment

Updated: 2026-06-10T10:16:49.959Z

NVD

Status : Analyzed

Published: 2026-06-09T17:17:32.460

Modified: 2026-06-11T18:51:33.450

Link: CVE-2026-45654

Redhat

No data.

OpenCVE Enrichment

Updated: 2026-08-02T02:00:13Z

Weaknesses

CWE-284
Improper Access Control

Impact

Affected Systems

Risk and Exploitability

Tracking

Attack Vector Local

Attack Complexity Low

Privileges Required High

Scope Changed

Confidentiality Impact High

Integrity Impact High

Availability Impact None

User Interaction None

Exploitation none

Automatable no

Technical Impact total

Subscriptions

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