Maxthon3 version 3.2.2 build 1000 and prior are vulnerable to cross context scripting (XCS) via the about:history page. The browser’s trusted zone improperly handles injected script content, allowing attackers to execute arbitrary JavaScript in a privileged context. This flaw enables modification of browser configuration and execution of arbitrary code through Maxthon’s exposed DOM APIs, including maxthon.program.Program.launch() and maxthon.io.writeDataURL(). Exploitation requires user interaction, typically by visiting a malicious webpage that triggers the injection.