CVE-2026-53579

CVE-2026-53579 is a sanitization gap in Trilium's default-on 'Safe import' filter: imported HTML is sanitized only for text notes, while 'book' notes are stored without sanitization and later rendered as HTML. An attacker who supplies a malicious import archive can embed a script payload in a book note; when a victim opens the containing note and it is displayed as a grid-view preview card, the payload is injected via jQuery's html() method and executes. In the web UI this yields stored cross-site scripting in the victim's session, and on the desktop client the Electron renderer runs with Node integration enabled, so the injected JavaScript escalates to full remote code execution on the victim's machine. All Trilium deployments on version 0.103.0 or earlier, both self-hosted server instances and desktop clients, are affected; triggering the flaw requires user interaction (importing an attacker-supplied archive and then opening the note). There is no public proof-of-concept, no known in-the-wild exploitation (EPSS 0.2%, not in CISA KEV), and the issue is fixed in version 0.104.0.

What to do: Upgrade to Trilium 0.104.0, which fixes the sanitization gap. Until upgraded, do not import archives from untrusted sources and review previously imported book notes for embedded HTML/scripts; users should be cautious opening imported book notes, especially in grid view. Desktop users should prioritize patching because exploitation there results in full code execution via the Node-integrated Electron renderer.