What’s Vulnerable › Vulnerabilities

CVE-2026-33066: SiYuan has Stored XSS to RCE via Unsanitized Bazaar README Rendering

• Severity: critical (CVSS 9.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-03-20 · updated 2026-06-17
• Weakness: CWE-79

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.

Affected products

• siyuan-note siyuan: before 3.6.1 — fixed in 3.6.1

How to fix

Upgrade to a fixed version: siyuan-note siyuan 3.6.1. Check the vendor advisory for mitigations.

References

• https://github.com/siyuan-note/siyuan/commit/b382f50e1880ed996364509de5a10a72d7409428
• https://github.com/siyuan-note/siyuan/security/advisories/GHSA-4663-4mpg-879v

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