SiYuan has a SVG Sanitizer Bypass via `<animate>` Element — Unauthenticated XSS
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.
Problem Types
| Type | CWE ID | Description |
|---|
| CWE | CWE-79 | CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') |
Type: CWE
Description: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Metrics
| Version | Base score | Base severity | Vector |
|---|
| 4.0 | 6.4 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N |
Version: 4.0
Base score: 6.4
Base severity: MEDIUM
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N