CVE-2026-66394
SiYuan before v3.7.3 contains stored and reflected cross-site scripting vulnerabilities in SVG sanitization that allows authenticated attackers to execute scripts by bypassing the HTML parser-based cleaner. Attackers can hide script tags within desc, style, or noscript elements which the HTML parser treats as raw text but browsers interpret as executable SVG content when served as image/svg+xml, enabling script execution in the application origin.
Published:Jul 27, 2026
Last Modified:Jul 28, 2026
EPS:Jul 27, 2026
EPSS Score:
CVSS Score:8.7
Affected Products
Vendor
Product
Action
Vendor
B3log
Product
Siyuan
B3log
Siyuan
Vendor
Siyuan
Product
Siyuan
Siyuan
Siyuan
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
Related CVEs
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
