CVE-2026-45585

MEDIUM

Microsoft Windows 11 Version 24H2 - Windows BitLocker Security Feature Bypass Vulnerability

Title source: rule
STIX 2.1

Exploitation Summary

EIP tracks 5 public exploits for CVE-2026-45585. PoCs published by Nightmare-Eclipse, Mclisterjoeh2o, andrei-majer.

AI-analyzed exploit summary This repository describes a BitLocker bypass vulnerability in Windows 11 and Server 2022/2025 via a crafted FsTx folder placed in the System Volume Information directory. The exploit leverages a component in the Windows Recovery Environment (WinRE) to spawn an unrestricted shell, bypassing BitLocker encryption.

Description

Microsoft is aware of a security feature bypass vulnerability in Windows publicly referred to as "YellowKey". The proof of concept for this vulnerability has been made public violating coordinated vulnerability best practices. We are issuing this CVE to provide mitigation guidance that can be implemented to protect against this vulnerability until the security update is made available.

Exploits (5)

github WORKING POC 3,663 stars
by Nightmare-Eclipse · pocgithub
https://github.com/Nightmare-Eclipse/YellowKey

This repository describes a BitLocker bypass vulnerability in Windows 11 and Server 2022/2025 via a crafted FsTx folder placed in the System Volume Information directory. The exploit leverages a component in the Windows Recovery Environment (WinRE) to spawn an unrestricted shell, bypassing BitLocker encryption.

Classification
Working Poc 90%
Attack Type
Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: Windows 11, Windows Server 2022/2025
No auth needed
Prerequisites: USB stick with NTFS/FAT32/exFAT filesystem · Access to target machine's boot process · Windows Recovery Environment (WinRE) access
devstral-2 · analyzed May 20, 2026 Full analysis →
github SUSPICIOUS 29 stars
by Mclisterjoeh2o · typescriptpoc
https://github.com/Mclisterjoeh2o/yellowkey-bitlocker

The repository claims to be a BitLocker bypass tool but contains no actual exploit code. It directs users to download an external ZIP file, which is a common tactic for distributing malware or fake exploits.

Classification
Suspicious 90%
Attack Type
Auth Bypass
Complexity
Theoretical
Reliability
Theoretical
Target: BitLocker (Windows 10/11)
No auth needed
Prerequisites: physical access · bootable USB
devstral-2 · analyzed May 23, 2026 Full analysis →
nomisec WORKING POC
by andrei-majer · poc
https://github.com/andrei-majer/bitlocker-hardening

This repository contains a PowerShell script that mitigates CVE-2026-45585 (YellowKey) by adding a TPM+PIN protector to BitLocker-protected drives, preventing the WinRE bypass attack. The script automates the process of setting Group Policy keys, applying them, and adding the TPM+PIN protector.

Classification
Working Poc 95%
Attack Type
Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: BitLocker on Windows 11 (24H2 or later) and Windows Server 2022/2025
Auth required
Prerequisites: Administrator privileges · BitLocker enabled on the target drive · Physical access to the machine
devstral-2 · analyzed May 24, 2026 Full analysis →
nomisec WORKING POC
by everest90909 · poc
https://github.com/everest90909/YellowKey-WinRE-Remediation

This repository contains functional PowerShell scripts for detecting and remediating CVE-2026-45585, a vulnerability involving the presence of 'autofstx.exe' in the WinRE BootExecute registry value, which could bypass BitLocker protections. The scripts mount the WinRE image, inspect/modify the offline SYSTEM hive, and ensure proper cleanup.

Classification
Working Poc 95%
Attack Type
Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: Windows Recovery Environment (WinRE) with BitLocker
Auth required
Prerequisites: Local administrator/SYSTEM privileges · 64-bit PowerShell · Access to reagentc.exe and reg.exe
devstral-2 · analyzed May 22, 2026 Full analysis →
nomisec WORKING POC
by bjbakker1984 · poc
https://github.com/bjbakker1984/Yellowkey-mitigation

This repository contains a PowerShell script that automates the mitigation for CVE-2026-45585 by removing 'autofstx.exe' from the BootExecute registry value in the WinRE (Windows Recovery Environment) hive. The script includes verification steps and only commits changes if modifications are necessary.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: Windows Recovery Environment (WinRE)
Auth required
Prerequisites: Administrator privileges · Windows system with WinRE enabled
devstral-2 · analyzed May 20, 2026 Full analysis →

References (2)

Core 2
Core References
Vendor Advisory vendor-advisory patch
Windows BitLocker Security Feature Bypass Vulnerability
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45585

Scores

CVSS v3 6.8
EPSS 0.0011
EPSS Percentile 28.1%
Attack Vector PHYSICAL
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact total

Details

CWE
CWE-77
Status published
Products (9)
Microsoft/Windows 11 Version 24H2 -
Microsoft/Windows 11 Version 25H2 -
Microsoft/Windows 11 version 26H1 -
Microsoft/Windows Server 2025 -
Microsoft/Windows Server 2025 (Server Core installation) -
microsoft/windows_11_24h2
microsoft/windows_11_25h2
microsoft/windows_11_26h1
microsoft/windows_server_2025
Published May 20, 2026
Tracked Since May 20, 2026