What is the CVSS score of CVE-2026-39310?

CVE-2026-39310 has a CVSS 3.1 base score of 8.6 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L. EPSS exploitation probability: 0.1%.

Which versions of Trilium Notes are affected by CVE-2026-39310?

A critical authentication bypass in Trilium Notes Desktop versions 0.102.1 and earlier exposes user notes to unauthorized access and modification by network-local attackers.. A patch is available.

How to fix or mitigate CVE-2026-39310?

Within 24 hours: Identify all systems running Trilium Notes Desktop and determine installed versions. Within 7 days: Upgrade all affected installations to version 0.102.2 or later. Within 30 days: Verify deployment completion and audit Clipper API access logs for suspicious activity.

Trilium Notes CVE-2026-39310

EUVD-2026-31156 HIGH

Improper Access Control (CWE-284)

2026-05-20 GitHub_M

Authentication Bypass CSRF Trilium Triliumnext

8.6

CVSS 3.1 · Vendor: GitHub_M

Severity by source

Vendor (GitHub_M) PRIMARY

8.6 HIGH

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

Primary rating from Vendor (GitHub_M) · only source for this CVE.

CVSS VectorVendor: GitHub_M

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

High

Availability

Low

Lifecycle Timeline

Patch available

May 20, 2026 - 20:02 EUVD

Source Code Evidence Fetched

May 20, 2026 - 20:01 vuln.today

Analysis Generated

May 20, 2026 - 20:01 vuln.today

DescriptionCVE.org

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.

AnalysisAI

Authentication bypass in Trilium Notes Desktop (Electron build) versions 0.102.1 and earlier allows remote unauthenticated attackers on the same network to access the Clipper API and read or manipulate notes without any credentials. The Electron runtime detection explicitly disables auth middleware on endpoints like /api/clipper/notes and the handshake endpoint, which fingerprints the application - no public exploit identified at time of analysis, but the vendor advisory GHSA-jcvx-vc83-cppw confirms the issue and the fix shipped in 0.102.2.

Technical ContextAI

Trilium Notes is a hierarchical personal knowledge base application built on Node.js with an Electron desktop wrapper (cpe:2.3:a:triliumnext:trilium). The Clipper API is a local HTTP service that normally accepts web-clipper browser-extension submissions; in the desktop build it binds to a high port (e.g. 37840) on all interfaces. The root cause maps to CWE-284 (Improper Access Control): runtime detection of the Electron environment branches around the authentication middleware entirely, so token, password, and CSRF checks are skipped for any caller - not just the local extension. Because the listener is reachable on the LAN rather than localhost-only, the bypass becomes network-exposed.

RemediationAI

Vendor-released patch: upgrade to Trilium 0.102.2 or later (https://github.com/TriliumNext/Trilium/releases/tag/v0.102.2), which restores authentication enforcement on the Clipper API under Electron and adds Electron fuses plus integrity checks per the release notes. If immediate upgrade is not possible, bind the desktop application to localhost only or block inbound TCP to the Clipper port (commonly 37840 and other high ports Trilium selects) at the host firewall - note this will break any LAN-based web-clipper extension workflow. Avoid running Trilium Desktop on untrusted networks (public Wi-Fi, conference networks, shared corporate LANs) until patched; the advisory at https://github.com/TriliumNext/Trilium/security/advisories/GHSA-jcvx-vc83-cppw should be consulted for full guidance.