Anonymous researcher publishes Windows BitLocker bypass and SYSTEM-level exploit after Patch Tuesday

An anonymous security researcher operating under the alias Nightmare-Eclipse has released technical details for two additional Windows vulnerabilities, escalating concerns within the security community over the accelerating pace of unsanctioned zero-day disclosures. The researcher, who previously exposed three Windows zero-days earlier this year, published details of YellowKey and GreenPlasma just days after Microsoft's monthly Patch Tuesday update, a timing that security professionals say maximizes exposure windows before patches become available.

YellowKey targets BitLocker encryption, the default full-disk encryption mechanism shipped with Windows Pro and Enterprise editions. Nightmare-Eclipse described the bypass as "one of the most insane discoveries I ever found," providing files designed to be loaded onto a USB drive. When the attacker executes the required key sequence on a targeted machine, the researcher claims it grants unrestricted shell access to a BitLocker-protected system. GreenPlasma, the second vulnerability disclosed, is described as a privilege escalation flaw that can deliver SYSTEM-level access to attackers. Security experts consulted by this publication warned that the release of substantial technical exploitation information substantially lowers the barrier for malicious actors to weaponize both flaws.

The pattern of disclosure raises fresh questions about coordinated vulnerability handling practices. Nightmare-Eclipse has now published five zero-day vulnerabilities within a single year, a cadence that complicates Microsoft's response timeline and potentially leaves enterprise environments exposed during critical patching windows. Organizations relying on BitLocker for data-at-rest protection face particular scrutiny, as the YellowKey bypass could undermine encryption assumptions that many security architectures are built upon. Microsoft has not yet issued a statement addressing these specific vulnerabilities.