CVE-2026-40107

Published: Apr 09, 2026 Last Modified: Apr 16, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 8,7
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Confidentiality: N/A
Integrity: N/A
Availability: N/A
MEDIUM 6,5
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: required
Scope: unchanged
Confidentiality: high
Integrity: none
Availability: none

Description

AI Translation Available

SiYuan is a personal knowledge management system. Prior to 3.6.4, SiYuan configures Mermaid.js with securityLevel: 'loose' and htmlLabels: true. In this mode, <img> tags with src attributes survive Mermaid's internal DOMPurify and land in SVG <foreignObject> blocks. The SVG is injected via innerHTML with no secondary sanitization. When a victim opens a note containing a malicious Mermaid diagram, the Electron client fetches the URL. On Windows, a protocol-relative URL (//attacker.com/image.png) resolves as a UNC path (\\attacker.com\image.png). Windows attempts SMB authentication automatically, sending the victim's NTLMv2 hash to the attacker. This vulnerability is fixed in 3.6.4.

EPSS (Exploit Prediction Scoring System)

Trend Analysis

EPSS (Exploit Prediction Scoring System)

Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.

EPSS Score
0,0005
Percentile
0,2th
Updated

EPSS Score Trend (Last 7 Days)

918

Server-Side Request Forgery (SSRF)

Incomplete
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Confidentiality Integrity Access Control
Potential Impacts:
Read Application Data Execute Unauthorized Code Or Commands Bypass Protection Mechanism
Applicable Platforms
Technologies: AI/ML, Web Based, Web Server
View CWE Details
Application

Siyuan by B3Log

Product Information
Vendor B3Log
Product Siyuan
Version Range Affected
To 3.6.4 (exclusive)
cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*
Common Platform Enumeration - Standardized vulnerability identification
https://github.com/siyuan-note/siyuan/security/advisories/G…
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-w95v-4h65-j455