by Kastro
Paper/Archive/CVE-2026-33066

CVE-2026-33066

siyuan-note siyuan — SiYuan has Stored XSS to RCE via Unsanitized Bazaar README Rendering

EPSS 0.6%public exploitCVSS 9.0
critical.is priorityof 100
47
CVSS 9.0 (NVD)9.0 / 10 × 3027.0Not in CISA KEV+300.0EPSS percentile 48.4.484 × 209.7Exploit: SSVC poc+1010.0SSVC exploitation: poc+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
siyuan< 3.6.1–CNA

Scores by source

NVD9.0CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
GitHub_M (CNA)5.3CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
CISA ADPSSVCExploitation: poc · Automatable: no · Technical impact: partial

References

refgithub.com/siyuan-note/siyuan/security/advisories/GHSA-4663-4mpg-879vrefgithub.com/siyuan-note/siyuan/commit/b382f50e1880ed996364509de5a10a72d7409428