Vulnerability Description
SiYuan is a personal knowledge management system. In versions 3.6.0 and below, SanitizeSVG has an incomplete blocklist — it blocks data:text/html and data:image/svg+xml in href attributes but misses data:text/xml and data:application/xml, both of which can render SVG with JavaScript execution. The unauthenticated /api/icon/getDynamicIcon endpoint serves user-controlled input (via the content parameter) directly into SVG markup using fmt.Sprintf with no escaping, served as Content-Type: image/svg+xml. This creates a click-through XSS: a victim navigates to a crafted URL, sees an SVG with an injected link, and clicking it triggers JavaScript via the bypassed MIME types. The attack requires direct navigation to the endpoint or <object>/<embed> embedding, since <img> tag rendering in the frontend doesn't allow interactive links. This issue has been fixed in version 3.6.1.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| B3Log | Siyuan | < 3.6.1 |
Related Weaknesses (CWE)
References
- https://github.com/advisories/GHSA-6865-qjcf-286fExploitThird Party Advisory
- https://github.com/siyuan-note/siyuan/commit/d01d561875d4f744e9f6232f1d4831e3642Patch
- https://github.com/siyuan-note/siyuan/releases/tag/v3.6.1Release Notes
- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-4mx9-3c2h-hwhgExploitMitigationVendor Advisory
FAQ
What is CVE-2026-32940?
CVE-2026-32940 is a vulnerability with a CVSS score of 9.3 (CRITICAL). SiYuan is a personal knowledge management system. In versions 3.6.0 and below, SanitizeSVG has an incomplete blocklist — it blocks data:text/html and data:image/svg+xml in href attributes but misses d...
How severe is CVE-2026-32940?
CVE-2026-32940 has been rated CRITICAL with a CVSS base score of 9.3/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-32940?
Check the references section above for vendor advisories and patch information. Affected products include: B3Log Siyuan.