CVE-2026-77438: Trilium is an open-source hierarchical note-taking application.

Trilium is an open-source hierarchical note-taking application.

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.

Description from the National Vulnerability Database, published by GitHub

What it means for a small business

If your business uses Trilium, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.42%, higher than 36% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 28, 2026, updated daily.

Check your own setup

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Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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