# CVE-2026-39310: Trilium Notes: Authentication Bypass in Clipper API for Electron (Desktop) Builds

> Attackers on shared networks can bypass authentication in Trilium Desktop's Clipper API to access notes and compromise the system.

- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 May 2026
- **Updated:** 21 May 2026
- **Also known as:** GHSA-jcvx-vc83-cppw

## What is CVE-2026-39310?

CVE-2026-39310 is a high-severity authentication bypass vulnerability in TriliumNext Trilium, published on 20 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-306 (Missing Authentication for Critical Functionality), CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2026-39310?


## How do I fix CVE-2026-39310?

No fix has been published for CVE-2026-39310 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-39310 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39310 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-39310 and fix it if it is affected.

What it is: CVE-2026-39310 is a high-severity authentication bypass vulnerability in TriliumNext Trilium, published on 20 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39310 exists.

Affected product: TriliumNext Trilium. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-39310/ (Markdown: https://insights.sbomify.com/CVE-2026-39310/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-39310
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-39310
- OSV: https://osv.dev/vulnerability/CVE-2026-39310

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-39310/
Summaries are generated and may contain mistakes; the official description above is the record.