CVE-2026-66396

critical · 9.3

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.

9.3

CVSS

0.4%

EPSS (exploit prob.)

31st

EPSS percentile

2026-07-27

Published

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Weaknesses

CWE-79

References

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-5rxg-wh59-mg34
https://www.vulncheck.com/advisories/siyuan-before-stored-xss-to-rce-via-title-img-ial
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-5rxg-wh59-mg34

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-66396