by Kastro
Paper/Archive/CVE-2026-40322

CVE-2026-40322

siyuan-note siyuan — SiYuan: Mermaid `javascript:` Link Injection Leads to Stored XSS and Electron RCE

EPSS 0.3%public exploitCVSS 9.1
critical.is priorityof 100
42
CVSS 9.1 (CNA)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 23.4.234 × 204.7Exploit: SSVC poc+1010.0SSVC exploitation: poc+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
siyuan< 3.6.4–CNA

Scores by source

GitHub_M (CNA)9.1CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: poc · Automatable: no · Technical impact: total

References

exploitgithub.com/siyuan-note/siyuan/security/advisories/GHSA-x63q-3rcj-hhp5refgithub.com/siyuan-note/siyuan/releases/tag/v3.6.4