CVE-2026-40107 - CERT CVE
ID CVE-2026-40107
Sažetak 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.
Reference
CVSS
Base: 6.5
Impact: 3.6
Exploitability:2.8
Pristup
VektorSloženostAutentikacija
NETWORK LOW NONE
Impact
PovjerljivostCjelovitostDostupnost
HIGH NONE NONE
CVSS vektor CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Zadnje važnije ažuriranje 16-04-2026 - 20:28
Objavljeno 09-04-2026 - 21:16