SiYuan is a personal knowledge management system. Prior to 3.5.10, SiYuan's SVG sanitizer (SanitizeSVG) blocks dangerous elements (<script>, <iframe>, <foreignobject>) and removes on* event handlers and javascript: in href attributes. However, it does NOT block SVG animation elements (<animate>, <set>) which can dynamically set attributes to dangerous values at runtime, bypassing the static sanitization.
This allows an attacker to inject executable JavaScript into the unauthenticated /api/icon/getDynamicIcon endpoint (type=8), creating a reflected XSS. This is a bypass of the fix for CVE-2026-29183 (fixed in v3.5.9). This vulnerability is fixed in v3.5.10.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
Passive
Minimal interaction
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
None
No disruption
CVSS Vector v4.0