SiYuan: Mermaid `javascript:` Link Injection Leads to Stored XSS and Electron RCE
Published Apr 16, 2026
9.1
CRITICALCVSS 3.1
EPSS 0.53%
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.
Affected products
-
- Version < 3.6.4StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Siyuan-Note | Siyuan | n/a |
|
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
References (3)
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-23330 Advisory
- https://github.com/siyuan-note/siyuan/releases/tag/v3.6.4 x_refsource_MISCRelease Notes
- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-x63q-3rcj-hhp5 exploitx_refsource_CONFIRMThird Party Advisory
| Link | Providers | Tags |
|---|---|---|
| https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-23330 | Advisory | |
| https://github.com/siyuan-note/siyuan/releases/tag/v3.6.4 | x_refsource_MISCRelease Notes | |
| https://github.com/siyuan-note/siyuan/security/advisories/GHSA-x63q-3rcj-hhp5 | exploitx_refsource_CONFIRMThird Party Advisory |
Change history (0)
No recorded changes yet.