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Improper Access ControlWeakness · CWE-284

CVE-2026-39310

HIGH · 8.6 CVSS v3.1 Published 2026-05-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Trilium Notes is a cross-platform, hierarchical note taking application focused on building large personal knowledge bases. In versions 0.102.1 and prior, the Clipper API in Trilium Desktop (v0.101.3) allows full authentication bypass when running in an Electron environment. When Trilium detects an Electron environment, it explicitly disables authentication middleware for the Clipper API, exposing endpoints such as /api/clipper/notes to the network with no password, API token, or CSRF protection. An attacker on a shared network (for example, a corporate LAN or public Wi-Fi) can scan for open high-range ports using a tool like nmap, since Trilium often binds to ports such as 37840. Once a candidate port is found, an unauthenticated request to the Clipper handshake endpoint, which also bypasses authentication, confirms a Trilium instance by returning the application name and protocol version. This facilitates unauthorized data access, phishing, and local system compromise. The issue has been fixed in version 0.102.2.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Trilium Notes versions 0.102.1 and prior contain an authentication bypass in the Clipper API when running in an Electron environment. The application explicitly disables authentication middleware for Clipper API endpoints (including /api/clipper/notes and the handshake endpoint) when it detects an Electron runtime, exposing these endpoints without password, API token, or CSRF protection on high-range ports (commonly 37840). An attacker on a shared network can discover the service via port scanning and access/modify notes without credentials.

MitigationUpgrade Trilium Notes to version 0.102.2 or later, which contains the fix for this authentication bypass. Until upgraded, restrict network access to the Trilium port from untrusted networks.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
High
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify if Trilium Notes is running
    Check for processes named 'trilium' or listening on common Trilium ports (e.g., port 37840 for Clipper API). Use commands like 'netstat -tlnp' or 'ss -tlnp' to list listening ports, or check if the Trilium process is running via task manager or 'ps aux | grep trilium'.
    Affected if Trilium Notes process is running and port 37840 (or a similar high-range port) is listening.
  2. Determine installed Trilium version
    Access the Trilium web interface and navigate to Options > About, or query the API endpoint /api/about if accessible. Alternatively, check the package.json or version file in the Trilium installation directory.
    Affected if The installed version is 0.102.1 or prior.
  3. Verify Clipper API port is exposed
    Scan for open ports in the high range (e.g., nmap -p 37840 <target-ip> or curl http://<target-ip>:37840). Check the Trilium configuration file (trilium-data options.json) for the 'clipperServer' setting and port configuration.
    Affected if Port 37840 (or configured Clipper port) is accessible from the network without authentication.
  4. Test unauthenticated handshake endpoint
    Send a GET request to the handshake endpoint: curl http://<target-ip>:37840/clipper/handshake (or the equivalent path based on your configuration). Observe if a response is returned containing the application name and protocol version without requiring credentials.
    Affected if The handshake endpoint returns application details (name, protocol version) without authentication, API token, or CSRF token.
  5. Confirm unauthenticated access to Clipper notes API
    Attempt a POST request to create or retrieve a note via the Clipper API without credentials: curl -X POST http://<target-ip>:37840/api/clipper/notes with a minimal JSON body. Verify if the request succeeds without authentication headers.
    Affected if The /api/clipper/notes endpoint accepts requests without password, API token, or CSRF protection.

A user is affected if Trilium Notes version 0.102.1 or prior is running with the Clipper API port (default 37840) exposed to an untrusted network, and the handshake or clipper notes endpoints respond without requiring authentication.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Trilium Notes to version 0.102.2 or later, which contains the fix for this authentication bypass. Until upgraded, restrict network access to the Trilium port from untrusted networks.

Recommended fix High confidence

0.102.2

  1. Identify all Trilium Notes instances running version 0.102.1 or prior in the environment
  2. Backup the Trilium data directory (typically in the user's application data folder) before upgrading
  3. Stop the running Trilium Notes application on all affected systems
  4. Download Trilium Notes version 0.102.2 or later from the official GitHub repository (github.com/zadam/trilium)
  5. Install version 0.102.2 by replacing the existing installation
  6. Restart the Trilium Notes application
  7. Verify the version is correctly showing 0.102.2 or later in the application
  8. As a temporary mitigation before upgrading, configure firewall rules to restrict access to the high-range port (default 37840) to trusted IP addresses only

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,570
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-39310 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data