CVE-2026-33066
9.0 · CRITICALOverview
CVE-2026-33066 is a critical-severity vulnerability affecting b3log siyuan. It was published on March 20, 2026 and has a CVSS 3.1 base score of 9.0 (CRITICAL).
This vulnerability has a CVSS 3.1 base score of 9.0, rated CRITICAL. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from b3log. Update siyuan to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| b3log | siyuan | >= 0, < 3.6.1 | Affected |
Frequently Asked Questions
What is CVE-2026-33066?
CVE-2026-33066 is a critical-severity vulnerability affecting b3log siyuan. It was published on March 20, 2026 and has a CVSS 3.1 base score of 9.0 (CRITICAL).
How severe is CVE-2026-33066?
This vulnerability has a CVSS 3.1 base score of 9.0, rated CRITICAL. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2026-33066?
Check the references section for vendor advisories and patches from b3log. Update siyuan to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-33066?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-33066 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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