CVE-2026-40322

9.0 CRITICAL
Published: April 16, 2026 Modified: April 20, 2026
View on NVD

Description

SiYuan is an open-source personal knowledge management system. In versions 3.6.3 and below, Mermaid diagrams are rendered with securityLevel set to "loose", and the resulting SVG is injected into the DOM via innerHTML. This allows attacker-controlled javascript: URLs in Mermaid code blocks to survive into the rendered output. On desktop builds using Electron, windows are created with nodeIntegration enabled and contextIsolation disabled, escalating the stored XSS to arbitrary code execution when a victim opens a note containing a malicious Mermaid block and clicks the rendered diagram node. This issue has been fixed in version 3.6.4.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/siyuan-note/siyuan/releases/tag/v3.6.4
Source: security-advisories@github.com
Release Notes
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-x63q-3rcj-hhp5
Source: security-advisories@github.com
Third Party Advisory
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-x63q-3rcj-hhp5
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Third Party Advisory

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
9.0 / 10.0
EPSS (Exploit Probability)
0.0%
14th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

b3log