cvedb.io
CVE-2026-40322
CRITICAL · CVSS 9
EPSS exploitation probability: 0%
Published 2026-04-16T23:16:33.733 · Last modified 2026-06-17T10:45:01.690

Summary

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 products

b3log — siyuan

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.