CVE-2026-66396 PUBLISHED

SiYuan before v3.7.2 Stored XSS to RCE via title-img IAL

Assigner: VulnCheck
Reserved: 26.07.2026 Published: 27.07.2026 Updated: 28.07.2026

SiYuan before v3.7.2 fails to escape the title-img Individual Attribute List value when rendering Gallery and Kanban cover images, allowing stored cross-site scripting via unescaped style attribute interpolation. Attackers with editor permissions can inject onload handlers that execute arbitrary code in the Electron renderer with full Node.js access when victims open affected documents.

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
CVSS Score: 9.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	High
Attack Complexity	Low	Integrity	High	Integrity	High
Attack Requirements	None	Availability	High	Availability	High
Privileges Required	High
User Interaction	Passive

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H
CVSS Score: 8.4

Attack Vector	Network	Scope	Changed
Attack Complexity	Low	Confidentiality Impact	High
Privileges Required	High	Integrity Impact	High
User Interaction	Required	Availability Impact	High

CVSS 3.1

Product Status

Vendor	siyuan-note
Product	siyuan
Versions	Default: unaffected affected from 0 to 3.7.2 (excl.) Version 3.7.2 is unaffected

Credits

hypnguyen1209 reporter

References

Problem Types

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') CWE