CVE-2026-33066

5.3 MEDIUM 0.6% exploit odds Fix listed XSS Device

What it is

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.

At a glance

Exploitability: Can be exploited over the network with a low-privilege account. Limited direct impact.
Exploit odds: 0.6% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-03-20 09:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 10:36 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.6% in the next 30 days (EPSS).
Severity: 5.3 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-03-20 09:16 UTC
Last modified: 2026-06-17 10:36 UTC
Exploit probability: 0.6% · EPSS, next 30 days
Weakness: CWE-79 · Cross-site scripting
Record status: Analyzed

Affected

b3log Siyuan < 3.6.1

Attack profile CVSS 4.0 · 5.3

Attack vector: Network
Complexity: Low
Attack requirements: None
Privileges needed: Low
User interaction: None
Confidentiality: None
Integrity: None
Availability: None

Raw vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-33066.md and follow it. Check whether this project is affected by CVE-2026-33066. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record