CVE-2026-34449

Critical

Description

SiYuan is a personal knowledge management system. Prior to version 3.6.2, a malicious website can achieve Remote Code Execution (RCE) on any desktop running SiYuan by exploiting the permissive CORS policy (Access-Control-Allow-Origin: * + Access-Control-Allow-Private-Network: true) to inject a JavaScript snippet via the API. The injected snippet executes in Electron's Node.js context with full OS access the next time the user opens SiYuan's UI. No user interaction is required beyond visiting the malicious website while SiYuan is running. This issue has been patched in version 3.6.2.

SeverityCritical
CVSS9.6
Exploit probability—
ProductB3log Siyuan
PublishedMar 31, 2026
First seenMar 31, 2026
Weakness typeCWE-942CWE-942

How to fix

Update
  • b3log siyuan3.6.2 or later
  • github.com/siyuan-note/siyuan/kernel3.6.2 or later

Affected products

ProductAffected versionsFixed in
b3log siyuanv < 3.6.23.6.2
github.com/siyuan-note/siyuan/kernelGov < 3.6.2, No range specified3.6.2

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