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CVE-2026-31807

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

Published: Mar 10, 2026Updated: Mar 11, 2026 Sources: CVE List NVD GHSACWE-79
NVD MITRE
6.1CVSSMEDIUM
EPSS Score
0.4%
Top 64.7%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
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Description

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.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:RS:CC:LI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:RUser Interaction
Required
Scope
S:CScope
Changed
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:NAvailability
None
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Weaknesses

CWE-79

Affected Products

siyuansiyuan-note
siyuanb3log
On-premWeb App
Web & CMS Plugins / cms-core
github.com/siyuan-note/siyuan/kernelGoOSS Libraries
b3logoss-projectWeb & CMS Pluginsaka b3log
gopackage-ecosystemOSS Libraries

Attack Graph

Products CVE Techniques Tactics

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Exploitability

Official Patch Available

MITRE ATT&CK

2 techniques
Execution
Initial Access
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References

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-5hc8-qmg8-pw27
github.com
https://nvd.nist.gov/vuln/detail/CVE-2026-31807
nvd.nist.gov
https://github.com/siyuan-note/siyuan
github.com
and 1 more references View all →

Timeline

Published
Mar 10, 2026
Last Updated
Mar 11, 2026

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