Security researcher Chaotic Eclipse has released a Windows BitLocker bypass tool named GreatXML, following a previously disclosed exploit targeting Microsoft Defender. The discovery was made accidentally and took four hours. A critical vulnerability exists for users who have used the Windows Defender Offline Scan feature, making them susceptible to the BitLocker bypass. The exploit involves copying an XML file and a recovery folder to the recovery partition and rebooting into the Windows Recovery Environment (WinRE). If the Defender offline scan was not initiated, users must log in to start it or find a way to boot into WinRE in offline scan state. GreatXML is the second BitLocker bypass tool released by Chaotic Eclipse, following the earlier exploit known as YellowKey (CVE-2026-45585), which has been patched by Microsoft.