Windows Secure Boot Protection Bypass Flaws
2026-06-09
Security feature bypass in Windows Secure Boot enables a high-privileged local attacker to circumvent boot-time integrity protections, undermining the chain of trust that prevents unauthorized firmware and bootloader code from executing. The flaw (CWE-693, Protection Mechanism Failure) carries a CVSS 7.9 rating driven by scope change and high confidentiality/integrity impact, and no public exploit identified at time of analysis. Because Secure Boot is the foundation for downstream protections like BitLocker, Virtualization-Based Security, and Measured Boot, bypass enables persistent pre-OS implants that survive reimaging.
Secure Boot bypass on Microsoft Windows allows an authorized local attacker with high privileges to defeat a platform integrity protection mechanism, leading to compromise of confidentiality and integrity outside the original security boundary. The scope-changed CVSS 7.9 rating reflects that successful exploitation breaks out of the Secure Boot trust domain, though no public exploit is identified at time of analysis and the issue is not listed in CISA KEV. Microsoft (secure@microsoft.com) issued the advisory via MSRC, and the weakness is classified as improper access control (CWE-284).
Security feature bypass in Microsoft Windows Secure Boot allows a local attacker with high privileges to defeat the platform's boot-time integrity protections, achieving cross-scope confidentiality and integrity impact on the host. The flaw is tracked under CWE-693 (Protection Mechanism Failure) and carries a CVSS 3.1 base score of 7.9 with no public exploit identified at time of analysis. Because the scope is Changed (S:C), successful exploitation lets the attacker influence components outside the originally vulnerable security boundary - typically the trusted boot chain itself.
Secure Boot bypass in Microsoft Windows allows an authorized local attacker with high privileges to defeat the firmware-level boot integrity protection, breaking the chain of trust intended to prevent unauthorized boot-time code. The CVSS 7.9 rating with scope change (S:C) indicates the bypass affects components beyond the initially compromised context, enabling pre-OS persistence. There is no public exploit identified at time of analysis and the issue is not listed in CISA KEV.
Secure Boot bypass in Microsoft Windows allows an authorized local attacker with high privileges to defeat the platform's protection mechanism and tamper with the pre-OS boot chain. The CVSS 7.9 score reflects a scope-changing impact on confidentiality and integrity from a local vector, and no public exploit identified at time of analysis. The single MSRC reference indicates a Microsoft-tracked issue that primarily threatens code-integrity and boot-trust guarantees rather than runtime availability.
Secure Boot bypass in Windows allows a local attacker with high privileges to defeat the platform's boot-time integrity protection mechanism, breaking the chain of trust that prevents unauthorized bootloaders and pre-OS code from executing. The flaw (CWE-693, Protection Mechanism Failure) carries a CVSS 7.9 due to scope change and high confidentiality/integrity impact, and no public exploit identified at time of analysis. Successful exploitation undermines a foundational anti-tamper control and can enable persistent pre-OS implants such as bootkits.
Security feature bypass in Windows Secure Boot allows a high-privileged local attacker to circumvent the boot integrity protection mechanism, undermining trust in the Windows boot chain. The flaw (CWE-1329, reliance on a component that is not updateable) carries a CVSS 7.9 rating due to scope change and high impact on confidentiality and integrity, and no public exploit has been identified at time of analysis. Successful exploitation could enable pre-OS persistence such as bootkits, defeating a foundational Windows security control.
Security feature bypass in Windows Secure Boot enables a local high-privileged attacker to defeat the platform's boot-time integrity protections, achieving high confidentiality and integrity impact across a changed security scope. The flaw stems from a protection mechanism failure (CWE-284, Improper Access Control) that undermines the trust boundary Secure Boot is designed to enforce. At the time of analysis, no public exploit has been identified and the issue is not listed in CISA KEV, but the scope-changed CVSS of 7.9 reflects the severity of subverting a root-of-trust security control.