CVE-2019-1294 — Windows Secure Boot Security Feature Bypass Vulnerability

Executive Summary

A security feature bypass exists when Windows Secure Boot improperly restricts access to debugging functionality. An attacker who successfully exploited this vulnerability could disclose protected kernel memory. To exploit the vulnerability, an attacker must gain physical access to the target system prior to the next system reboot. The security update addresses the vulnerability by preventing access to certain debugging options when Windows Secure Boot is enabled.

Overview

5.3

CVSS MEDIUM

Important

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Security Feature Bypass

Released Sep 10 2019

Last Updated Sep 10 2019

Publicly Disclosed Yes

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.01221 — 0.64759 percentile

CVSS Vector

ATTACK VECTOR

Physical

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

None

USER INTERACTION

None

SCOPE

Changed

Temporal Score: 4.8

EPSS Score

0.01221

probability of exploitation in the next 30 days

0.64759 percentile - updated 2026-06-20

View on FIRST.org

Affected Products

13 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows 10 Version 1803 for 32-bit Systems	`4516058 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1803 for ARM64-based Systems	`4516058 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1803 for x64-based Systems	`4516058 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1809 for 32-bit Systems	`4512578 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1809 for ARM64-based Systems	`4512578 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1809 for x64-based Systems	`4512578 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1903 for 32-bit Systems	`4515384 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1903 for ARM64-based Systems	`4515384 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1903 for x64-based Systems	`4515384 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2019	`4512578 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2019 (Server Core installation)	`4512578 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server, version 1803 (Server Core Installation)	`4516058 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server, version 1903 (Server Core installation)	`4515384 (Security Update)`	Important	Security Feature Bypass	Yes

Patches

3 patches

Article	Type	Restart
`4516058`	Security Update	Yes
`4512578`	Security Update	Yes
`4515384`	Security Update	Yes

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

Microsoft has not published researcher acknowledgments for this CVE, or they are not yet reflected in our data source. Check the MSRC advisory directly for the most current credit information.

References

MSRC Advisory MITRE NVD