Trilium is an open-source hierarchical note-taking application. In versions up to and including 0.103.0, the default-on "Safe import" filter sanitizes HTML only for text notes and excludes the book note type, whose content is stored without sanitization and later rendered as HTML, allowing an attacker-supplied import archive to embed a payload that executes as script. A book note's content is routed through the same rendering path as text notes and injected into the page with jQuery's html method when the note is shown as a grid-view preview card, so a malicious note survives Safe import and runs as soon as the victim opens the containing note. On the desktop client the Electron renderer runs with Node integration enabled, so the injected JavaScript escalates from cross-site scripting to full remote code execution on the victim's machine. This issue is fixed in version 0.104.0.