CVE-2026-40322
criticalpriority · track · 0EPSS 0.003 · 23 %ileEUUSEPSS · scored 2026-10-27
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
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8.2–9.1
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (2)
Products and version ranges known to be affected.
also known as (2)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (6)
External citations — patches, advisories, analysis.
- https://b3log.org/siyuan/Patchcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2026-40322cnnvd
- https://github.com/siyuan-note/siyuan/releases/tag/v3.6.4enisa_euvd
- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-x63q-3rcj-hhp5enisa_euvd
- https://github.com/siyuan-note/siyuan/releases/tag/v3.6.4Release Notesnvd
- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-x63q-3rcj-hhp5Third Party Advisorynvd
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