Local Secure Boot bypass via undisclosed mechanism
Published Jun 9, 2026 · Updated Jun 9, 2026
A protection mechanism failure in Microsoft Windows UEFI allows local users with low privileges to bypass Secure Boot security controls. Microsoft has not published the affected UEFI locus or the operation that fails to enforce the protection. Exploitation requires local access and low privileges without user interaction; successful bypass can compromise confidentiality, integrity, and availability.
Summary
What happened
A protection mechanism failure in Microsoft Windows UEFI allows local users with low privileges to bypass Secure Boot security controls. Microsoft has not published the affected UEFI locus or the operation that fails to enforce the protection. Exploitation requires local access and low privileges without user interaction; successful bypass can compromise confidentiality, integrity, and availability.
The record
- CVE
- CVE-2026-45656
- Published
- Jun 9, 2026
- Updated
- Jun 9, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-693, T1542.003
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 9, 2026CVE publishedPublication date reported by the CVE source.
- Jun 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.17763.0 <10.0.17763.8880
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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