CVE-2026-40322

CRITICAL EPSS 22.3%
Published Apr 16, 20262mo ago · Modified Jun 17, 20262w ago
9.0 CVSS 3.1
Critical
Find Similar
Published Apr 16, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

Description

SiYuan is an open-source personal knowledge management system. In versions 3.6.3 and below, Mermaid diagrams are rendered with securityLevel set to "loose", and the resulting SVG is injected into the DOM via innerHTML. This allows attacker-controlled javascript: URLs in Mermaid code blocks to survive into the rendered output. On desktop builds using Electron, windows are created with nodeIntegration enabled and contextIsolation disabled, escalating the stored XSS to arbitrary code execution when a victim opens a note containing a malicious Mermaid block and clicks the rendered diagram node. This issue has been fixed in version 3.6.4.

CVSS Details

Base Score
9.0
Exploitability
2.3
Impact
6.0
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction Required
Scope Changed
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
22.3% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 2

CWE-79 Cross-site Scripting Injection
CWE-94 Improper Control of Generation of Code (Code Injection) Injection

Affected Products 1

VendorProductVersionRange
b3logsiyuan* <3.6.4

References 2

  • github.com https://github.com/siyuan-note/siyuan/releases/tag/v3.6.4
    Release Notes
  • github.com https://github.com/siyuan-note/siyuan/security/advisories/GHSA-x63q-3rcj-hhp5
    Third Party Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.