What’s Vulnerable › Vulnerabilities

CVE-2026-100643: SiYuan before v3.8.4 Stored XSS via Attribute View textarea

• Severity: high (CVSS 8.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-26 · updated 2026-09-28
• Weakness: CWE-79

Description

SiYuan versions before v3.8.4 fail to properly escape four stored Attribute View values in textarea elements, allowing authenticated attackers to inject JavaScript by modifying field descriptions, template sources, select option descriptions, or footer calculation templates. Attackers can execute stored JavaScript when other users open affected database menus, and in the Electron desktop app with nodeIntegration enabled, this leads to command execution with SiYuan process privileges.

Affected products

• siyuan-note siyuan: from 2.10.8 before 3.8.4 — fixed in 3.8.4

How to fix

Upgrade to a fixed version: siyuan-note siyuan 3.8.4. Check the vendor advisory for mitigations.

References

• https://github.com/siyuan-note/siyuan/security/advisories/GHSA-h3p6-c22r-fx2j
• https://www.vulncheck.com/advisories/siyuan-before-3.8.4-stored-xss-via-attribute-view-textarea
• https://github.com/siyuan-note/siyuan/security/advisories/GHSA-h3p6-c22r-fx2j

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