Critical Windows Zero-Day Vulnerabilities Uncovered: 'YellowKey' and 'GreenPlasma'
In May 2026, a security researcher known as 'Nightmare Eclipse' disclosed multiple zero-day vulnerabilities affecting Windows systems, including 'YellowKey' and 'GreenPlasma'. 'YellowKey' allows attackers with physical access to bypass BitLocker encryption using a USB device, while 'GreenPlasma' enables local privilege escalation to SYSTEM level by exploiting the Windows CTFMON input service. These vulnerabilities expose critical weaknesses in Windows security mechanisms, potentially leading to unauthorized data access and system control. The rapid disclosure of these zero-days, some of which are actively exploited, underscores the urgency for organizations to implement robust security measures beyond patching, such as enforcing physical security controls, applying the principle of least privilege, and enhancing monitoring for anomalous activities.
Kill Chain