CVE-2026-48578: Microsoft Windows Secure Boot protection mechanism failure

CVE-2026-48578 · Severity: high · CVSS 7.9 · Published 2026-06-09

A security flaw in Windows Secure Boot could allow an attacker with administrative privileges to bypass critical boot-time protections. Secure Boot is designed to ensure that a computer boots using only software that is trusted by the hardware manufacturer. If exploited, an attacker could potentially install persistent malicious software that remains hidden even if the operating system is reinstalled.

Technologies: Microsoft Windows Secure Boot. Vendors: Microsoft.

Quick answers

Is CVE-2026-48578 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-48578 being exploited in the wild.
How severe is CVE-2026-48578?
High severity, with a CVSS score of 7.9, published 9 June 2026.
Which products and versions are affected?
Microsoft Windows Secure Boot.
Is there a fix for CVE-2026-48578?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-48578 attacked?
It is attacked with local access, in an operating system.
Am I affected by CVE-2026-48578?
Check whether you run Microsoft Windows Secure Boot. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A protection mechanism failure exists in Windows Secure Boot, classified as improper access control (CWE-284). The vulnerability allows a local attacker with administrative or high-level privileges (PR:H) to bypass Secure Boot integrity checks. By successfully exploiting this flaw, an attacker can undermine the Root of Trust and potentially execute unsigned or malicious code during the boot process. The vulnerability has a CVSS score of 7.9, reflecting a high impact on confidentiality and integrity with a scope change (S:C), though it requires local access. Microsoft has released information regarding this vulnerability via their Security Update Guide.

Affected products

  • Microsoft Windows Secure Boot

Timeline

  • 2026-06-09: advisory: Advisory published by Microsoft and NVD.

References

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