Vulnerability Description
SiYuan is a personal knowledge management system. In versions 3.6.0 and below, the backend renderREADME function uses lute.New() without calling SetSanitize(true), allowing raw HTML embedded in Markdown to pass through unmodified. The frontend then assigns the rendered HTML to innerHTML without any additional sanitization. A malicious package author can embed arbitrary JavaScript in their README that executes when a user clicks to view the package details. Because SiYuan's Electron configuration enables nodeIntegration: true with contextIsolation: false, this XSS escalates directly to full Remote Code Execution. The issue was patched 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/siyuan-note/siyuan/commit/b382f50e1880ed996364509de5a10a72d74Patch
- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-4663-4mpg-879vExploitMitigationVendor Advisory
FAQ
What is CVE-2026-33066?
CVE-2026-33066 is a vulnerability with a CVSS score of 9.0 (CRITICAL). SiYuan is a personal knowledge management system. In versions 3.6.0 and below, the backend renderREADME function uses lute.New() without calling SetSanitize(true), allowing raw HTML embedded in Markdo...
How severe is CVE-2026-33066?
CVE-2026-33066 has been rated CRITICAL with a CVSS base score of 9.0/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-33066?
Check the references section above for vendor advisories and patch information. Affected products include: B3Log Siyuan.