CyberSecBulletin
CVE-2026-77438NVD status: Analyzed

Trilium: Exposure of Sensitive Information to an Unauthorized Actor

CVE-2026-77438 is a high-severity exposure of sensitive information to an unauthorized actor vulnerability in Trilium from TriliumNext, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Trilium versions: < 0.104.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.42% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Trilium you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
TriliumNextTrilium< 0.104.0Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by CNA (github.com).

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Exposure of Sensitive Information to an Unauthorized Actor

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

How developers prevent this class of flaw

  • Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

More Exposure of Sensitive Information to an Unauthorized Actor vulnerabilities (CWE-200)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Trilium

All Trilium vulnerabilities

Recent Exposure of Sensitive Information to an Unauthorized Actor vulnerabilities

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