CVE-2026-29183

CRITICAL 9.3

SiYuan: Unauthenticated reflected SVG XSS in `/api/icon/getDynamicIcon` (`type=8`) enables arbitrary JavaScript execution

CVSS Score

9.3

EPSS Score

0.0%

EPSS Percentile

0th

SiYuan is a personal knowledge management system. Prior to version 3.5.9, an unauthenticated reflected XSS vulnerability exists in the dynamic icon API endpoint "GET /api/icon/getDynamicIcon" when type=8, attacker-controlled content is embedded into SVG output without escaping. Because the endpoint is unauthenticated and returns image/svg+xml, a crafted URL can inject executable SVG/HTML event handlers (for example onerror) and run JavaScript in the SiYuan web origin. This can be chained to perform authenticated API actions and exfiltrate sensitive data when a logged-in user opens the malicious link. This issue has been patched in version 3.5.9.

CWE	CWE-79
Vendor	siyuan-note
Product	siyuan
Published	Mar 6, 2026
Last Updated	Mar 6, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

Affected Versions

siyuan-note / siyuan

< 3.5.9

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/siyuan-note/siyuan/security/advisories/GHSA-6865-qjcf-286f