Lumiverse is a full-featured AI chat application. Prior to 0.9.7, the component override system transpiles user-supplied TSX via Sucrase and evaluates it with new Function, shadowing dangerous globals (fetch, window, eval, etc.) with undefined. A static source validator (validateComponentOverrideSource) additionally blocks these identifiers by word-boundary regex. Both controls are bypassed. String-split bypass of the static validator: any blocked identifier can be reconstructed at runtime from string fragments ('ownerDoc' + 'ument'). DOM ref escape from the sandbox: useRef and useEffect are provided in scope. A ref attached to a rendered element gives a live DOM node. From any real DOM node, node['ownerDoc'+'ument']['def'+'aultView'] yields the real window, bypassing all identifier shadows. Theme packs (.lumitheme / .lumiverse-theme) are the shareable delivery mechanism. A malicious pack is an exploit path: the victim imports the file, enables one component override in the Theme Editor, and the payload fires in their authenticated session.This vulnerability is fixed in 0.9.7.