CVE-2026-33066

CRITICAL

SiYuan has Stored XSS to RCE via Unsanitized Bazaar README Rendering

Title source: cna
STIX 2.1

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.

Scores

CVSS v3 9.0
EPSS 0.0009
EPSS Percentile 26.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-79
Status published
Products (3)
b3log/siyuan < 3.6.1
siyuan-note/siyuan 0 - 0.0.0-20260314111550-b382f50e1880Go
siyuan-note/siyuan < 3.6.1
Published Mar 20, 2026
Tracked Since Mar 20, 2026