CVE-2026-23847: SiYuan Vulnerable to Reflected Cross-Site Scripting (XSS) via /api/icon/getDynamicIcon

Description

SiYuan is a personal knowledge management system. Versions prior to 3.5.4 are vulnerable to reflected cross-site scripting in /api/icon/getDynamicIcon due to unsanitized SVG input. The endpoint generates SVG images for text icons (type=8). The content query parameter is inserted directly into the SVG <text> tag without XML escaping. Since the response Content-Type is image/svg+xml, injecting unescaped tags allows breaking the XML structure and executing JavaScript. Version 3.5.4 patches the issue.]

CVSS vector

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

Attack vector

Network

Complexity

Low

Privileges

None

User interaction

Required

Confidentiality

Low

Integrity

Low

Availability

None

Scope

Changed

Exploitation

Is it being used?

Exploit prediction (EPSS)0.3% · higher than 24% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

SI

siyuan · siyuan-note

< 3.5.4 · source: vendor, NVD