CVE-2026-39311

What it is

Trilium Notes is a cross-platform, hierarchical note taking application focused on building large personal knowledge bases. Versions 0.102.1 and prior contain a critical security flaw where lack of SVG sanitization combined with a disabled Content Security Policy (CSP) and a publicly reachable backend execution API results in an unauthenticated Remote Code Execution (RCE). The vulnerability arises from an insecure-by-design architecture: Trilium serves SVG attachments with the image/svg+xml MIME type without any sanitization, and it explicitly disables Helmet's Content Security Policy middleware, removing the primary defense against script execution in served assets. Because the malicious SVG runs under the Same-Origin Policy, it can issue a fetch('/') to extract the csrfToken from the document body. With that token, it can send a signed request to /api/script/exec to execute arbitrary Node.js code on the server. An attacker can compromise the entire server instance simply by tricking an authenticated user into viewing a shared SVG attachment. The issue has been fixed in version 0.102.2.

At a glance

Exploitability

Can be exploited over the network with an admin-level account, but needs a user to act. High risk of service disruption.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-05-20 20:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-23 12:10 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.3% in the next 30 days (EPSS).
• Severity: 6.8 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-05-20 20:16 UTC

Last modified

2026-07-23 12:10 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-79 · Cross-site scripting

Record status

Deferred

Attack profile CVSS 3.1 · 6.8

Attack vector

Network

Complexity

High

Privileges needed

High

User interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-39311.md and follow it. Check whether this project is affected by CVE-2026-39311. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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