CVE Tools
Sign in

CVE-2026-34449

SiYuan: Cross-Origin RCE via Permissive CORS Policy and JavaScript Snippet Injection

Published: Mar 31, 2026Updated: Apr 3, 2026 Sources: CVE List NVDCWE-942
NVD MITRE
9.6CVSSCRITICAL
EPSS Score
0.5%
Top 61.3%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

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.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:RS:CC:HI:HA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:RUser Interaction
Required
Scope
S:CScope
Changed
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-942

Affected Products

siyuanb3log
On-premWeb App
Web & CMS Plugins / cms-core
siyuansiyuan-note
b3logoss-projectWeb & CMS Pluginsaka b3log

Exploitability

Official Patch Available

References

https://github.com/siyuan-note/siyuan/issues/17246
github.com
https://github.com/siyuan-note/siyuan/releases/tag/v3.6.2
github.com
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-68p4-j234-43mv
github.com

Timeline

Published
Mar 31, 2026
Last Updated
Apr 3, 2026

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2026-34449 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows