Description

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.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.5",
  "pubDate": "2026-08-27T20:18:39.407Z",
  "pubdate": "2026-08-27T20:18:39.407Z",
  "executiveSummary": "Trilium versions up to and including 0.103.0 contain an information disclosure vulnerability within the public share-search endpoint. The flaw allows unauthenticated attackers to bypass access controls, including share credentials and hidden-from-tree configurations, to retrieve sensitive information from protected notes.\nThe vulnerability stems from improper authorization checks during full-text search operations across published subtrees. By submitting queries to the search endpoint, an unauthenticated user can perform Boolean-based inference to recover the full contents of password-protected or restricted notes.\nThe impact is critical, as it facilitates unauthorized data exfiltration, compromising the confidentiality of user notes. The vulnerability requires no authentication and is accessible via standard network requests to the affected endpoint. Users are strongly advised to upgrade to version 0.104.0 to resolve this security flaw.",
  "technicalDetails": "The vulnerability is located in the public share-search endpoint of the Trilium application. The root cause is a failure in the backend authorization logic; while the system performs an initial validation check on the ancestor note provided in the search request, it fails to perform granular, per-note authorization checks for individual nodes within the requested subtree.\nWhen a search query is executed, the application performs a full-text search across the published tree. The current implementation assumes that if the root or ancestor node is accessible, the children should be implicitly accessible as well. Consequently, the search results include titles, hierarchical paths, and content snippets for notes that should otherwise be protected by 'shareCredentials' or marked as 'shareHiddenFromTree'.\nExploitation is straightforward and does not require elevated privileges or authentication. An attacker can craft arbitrary search queries to identify the existence and contents of protected notes. Because the search function returns metadata and partial content upon a match, an attacker can leverage this as a boolean oracle. By iteratively refining search strings and observing whether the endpoint returns a successful match, the attacker can systematically reconstruct the sensitive content of notes meant to be gated by authentication.\nThe attack flow proceeds as follows: 1) The attacker targets the public share-search endpoint. 2) The attacker submits a search query designed to match sensitive data. 3) The backend processes the query across the entire published subtree, ignoring individual note-level restrictions. 4) The application returns the search results, revealing data from notes that the attacker should not be able to view. 5) By observing the presence or absence of search hits, the attacker performs content inference/exfiltration.\nThis vulnerability affects all Trilium versions up to and including 0.103.0. The lack of re-validation for individual search results allows for significant data leakage, posing a high risk to environments where public notes may contain links to or associations with sensitive internal information."
}