Trilium is an open-source hierarchical note-taking application. In versions up to and including 0.103.0, the default-on "Safe import" filter does not sanitize note titles, and the GeoMap note view interpolates a marker note's title into raw HTML that is rendered as innerHTML, allowing an attacker-supplied import archive to inject script that runs when the map is displayed. Because Safe import neutralizes scripts but never escapes titles, a note whose title contains an HTML event-handler payload survives the import and executes as soon as the victim opens the GeoMap that renders its marker. 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.

Trilium is an open-source hierarchical note-taking application. In versions prior to 0.104.0, the automatic image-download feature accepts file:// URLs in a note's img tags and reads the referenced local file with no path validation, allowing any authenticated user to disclose arbitrary files readable by the Trilium process. When a text note is saved, Trilium scans its HTML for image sources and downloads each external one; because the HTML sanitizer keeps file as an allowed scheme, a source such as file:///etc/passwd is passed straight to a filesystem read and its contents are stored as a note attachment the user can then retrieve. Pointing the same primitive at an unbounded source such as /dev/zero causes uncontrolled memory allocation that crashes the server process. The feature is enabled by default and is reachable through the web UI, the ETAPI, the web clipper, and note imports, requiring only an authenticated session or an ETAPI token. This issue is fixed in version 0.104.0

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.

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 mindMap note type, whose JSON content is stored without sanitization, allowing an attacker-supplied import archive to embed a payload that renders as arbitrary HTML. A mind map node can carry a dangerouslySetInnerHTML property that the Mind Elixir library assigns directly to a node's innerHTML, so a malicious note survives Safe import and executes script as soon as the victim opens the imported mind map. 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.

Trilium is an open-source hierarchical note-taking application. In versions up to and including 0.103.0, the public share-search endpoint does not enforce the per-note shareCredentials and shareHiddenFromTree controls, allowing an unauthenticated visitor to read the titles, tree paths, and content of protected shared notes. The endpoint authorizes only the ancestor note supplied in the request and then runs a full-text search across the entire published subtree, returning each matching note's title, share identifier, and hierarchical path without re-checking whether that individual note requires a share password or is hidden from the navigation tree. Because the search matches note content, an attacker can enumerate protected notes and use the endpoint as a boolean oracle that confirms arbitrary substrings, recovering the full contents of notes that should be gated behind a password. This issue is fixed in version 0.104.0.

Trilium is an open-source hierarchical note-taking application. In versions prior to 0.104.0, the default-on "Safe import" filter fails to neutralize the shareTemplate relation because that relation is not marked as dangerous, allowing an attacker-supplied import archive to plant a server-side template that leads to remote code execution. The relation is omitted from the built-in list of dangerous attributes, so unlike other code-loading relations it is not disabled on import, and when the victim later publishes the imported note the public share renderer feeds the linked EJS code note's raw bytes into ejs.render, which compiles them in the server's Node process. An unauthenticated request to the shared note then executes the attacker's JavaScript with full access to require, process, the filesystem, and the network. This issue is fixed in version 0.104.0.

Trilium Notes is a cross-platform, hierarchical note taking application focused on building large personal knowledge bases. Prior to 0.103.0, the #iconClass label value is returned raw by getNoteIcon() and inserted without HTML attribute encoding into class attributes in apps/client/src/widgets/quick_search.ts and apps/client/src/services/note_autocomplete.ts, allowing a stored payload to execute automatically when a victim opens a new tab or uses Ctrl+J and, because Electron enables nodeIntegration and disables contextIsolation, run operating-system commands as the victim. This issue is fixed in version 0.103.0.