Windows 11’s June update shuts down an intentional BitLocker backdoor with full file access — here’s what changed
Microsoft’s June 2026 Patch Tuesday update addresses a critical vulnerability in Windows 11’s BitLocker encryption feature that allegedly contained an intentional backdoor. The vulnerability, known as YellowKey, was discovered and publicly disclosed by security researcher “Chaotic Eclipse” (also known as Nightmare-Eclipse) and allowed attackers to gain full access to BitLocker-protected drives using only a simple USB key.
The June update patches three zero-day exploits disclosed by the researcher: YellowKey, GreenPlasma, and MiniPlasma. The YellowKey vulnerability was particularly concerning not only for its technical implications but also for the researcher’s assertion that Microsoft deliberately included the backdoor in the security feature itself, raising serious questions about the integrity of a security mechanism millions of users rely on.
Microsoft has issued a mitigation to restore trust in BitLocker following the disclosure. The patch represents a significant security update for Windows 11 users, addressing what could have been a severe risk to data protected by the encryption standard. Users with BitLocker-encrypted drives are advised to apply the June 2026 update to ensure their systems are protected against potential exploitation of these vulnerabilities.
This incident highlights the ongoing tension between security research disclosure and responsible patching in the technology industry, as well as the importance of regular security updates for protecting sensitive user data.