CVE-2026-33067: SiYuan has Stored XSS to RCE via Unsanitized Bazaar Package Metadata

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. Versions 3.6.0 and below render package metadata fields (displayName, description) using template literals without HTML escaping. A malicious package author can inject arbitrary HTML/JavaScript into these fields, which executes automatically when any user browses the Bazaar page. Because SiYuan's Electron configuration enables nodeIntegration: true with contextIsolation: false, this XSS escalates directly to full Remote Code Execution on the victim's operating system — with zero user interaction beyond opening the marketplace tab. This issue has been fixed 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

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