CVE-2026-40322

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.

CVSS v3 9.0 CRITICAL

9.0^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 2.3 / Impact : 6.0

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

References

Link	Resource
https://github.com/siyuan-note/siyuan/releases/tag/v3.6.4	Release Notes
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-x63q-3rcj-hhp5	Third Party Advisory
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-x63q-3rcj-hhp5	Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-04-16 23:16

Updated : 2026-06-17 10:45

NVD link : CVE-2026-40322

Mitre link : CVE-2026-40322

CVE.ORG link : CVE-2026-40322

JSON object : View

Products Affected

b3log

siyuan

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CWE-94

Improper Control of Generation of Code ('Code Injection')

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