CVE-2025-55338 — Windows BitLocker Security Feature Bypass Vulnerability

Executive Summary

Missing Ability to Patch ROM Code in Windows BitLocker allows an unauthorized attacker to bypass a security feature with a physical attack.

Overview

4.6

CVSS MEDIUM

Important

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Security Feature Bypass

Released Oct 14 2025

Last Updated Oct 14 2025

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.02891 — 0.85082 percentile

NVD CVSS 4.6 MEDIUM — differs from MSRC

CVSS Vector

CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C

ATTACK VECTOR

Physical

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

None

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

High

INTEGRITY

High

AVAILABILITY

None

EXPLOIT CODE MATURITY

Unproven

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 5.3

EPSS Score

0.02891

probability of exploitation in the next 30 days

0.85082 percentile - updated 2026-06-21

View on FIRST.org

Affected Products

29 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows 10 for 32-bit Systems	`5066837 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 for x64-based Systems	`5066837 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1607 for 32-bit Systems	`5066836 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1607 for x64-based Systems	`5066836 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1809 for 32-bit Systems	`5066586 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1809 for x64-based Systems	`5066586 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 21H2 for 32-bit Systems	`5066791 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 21H2 for ARM64-based Systems	`5066791 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 21H2 for x64-based Systems	`5066791 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 22H2 for 32-bit Systems	`5066791 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 22H2 for ARM64-based Systems	`5066791 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 22H2 for x64-based Systems	`5066791 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 11 Version 22H2 for ARM64-based Systems	`5066793 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 11 Version 22H2 for x64-based Systems	`5066793 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 11 Version 23H2 for ARM64-based Systems	`5066793 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 11 Version 23H2 for x64-based Systems	`5066793 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 11 Version 24H2 for ARM64-based Systems	`5066835 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 11 Version 24H2 for x64-based Systems	`5066835 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 11 Version 25H2 for ARM64-based Systems	`5066835 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 11 Version 25H2 for x64-based Systems	`5066835 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2016	`5066836 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2016 (Server Core installation)	`5066836 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2019	`5066586 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2019 (Server Core installation)	`5066586 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2022	`5066782 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2022 (Server Core installation)	`5066782 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2022, 23H2 Edition (Server Core installation)	`5066780 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2025	`5066835 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2025 (Server Core installation)	`5066835 (Security Update)`	Important	Security Feature Bypass	Yes

Patches

8 patches

Article	Type	Restart
`5066837`	Security Update	Yes
`5066836`	Security Update	Yes
`5066586`	Security Update	Yes
`5066791`	Security Update	Yes
`5066793`	Security Update	Yes
`5066835`	Security Update	Yes
`5066782`	Security Update	Yes
`5066780`	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

Netanel Ben Simon with Microsoft (STORM), Alon Leviev

References

MSRC Advisory MITRE NVD