CVE-2026-31807CWE-79

SiYuan has a SVG Sanitizer Bypass via `<animate>` Element — Unauthenticated XSS

Medium · published March 10, 2026

CVSS v4.0
6.4
EPSS
1%
Percentile
42.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
6.4 · 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
EPSS
0.00501 · 42.0th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-03-10T20:56Z
EPSS history
Timeline
  • 10 MAR 20:56Z
    SiYuan has a SVG Sanitizer Bypass via `<animate>` Element — Unauthenticated XSS
    cvelistv5