Local Secure Boot bypass via undisclosed mechanism
Published Jun 9, 2026 · Updated Jun 9, 2026
Protection mechanism failure in Windows Secure Boot allows local users with administrative privileges to bypass boot trust checks. Microsoft has not disclosed the affected Secure Boot locus or the incorrect operation that accepts untrusted boot material. Exploitation requires local high privileges and allows unauthorized boot content to cross the Secure Boot trust boundary, exposing confidentiality and integrity without reported availability impact.
Summary
What happened
Protection mechanism failure in Windows Secure Boot allows local users with administrative privileges to bypass boot trust checks. Microsoft has not disclosed the affected Secure Boot locus or the incorrect operation that accepts untrusted boot material. Exploitation requires local high privileges and allows unauthorized boot content to cross the Secure Boot trust boundary, exposing confidentiality and integrity without reported availability impact.
The record
- CVE
- CVE-2026-48570
- Published
- Jun 9, 2026
- Updated
- Jun 9, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-693, T1542.003
- Attack vector
- local
- Privileges
- admin
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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