CVE-2026-93923

EUVD-2026-83459
SiYuan through 3.8.4 fails to escape heading style attributes when rendering outline and bookmark dock HTML, allowing stored cross-site scripting. Attackers can supply crafted notebooks or call administrative endpoints to inject malicious style values that execute in the Electron renderer with full system access.
Cross-site Scripting
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
8.8 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: 35.44%
Common Weakness Enumeration
References
https://github.com/siyuan-note/siyuan
https://github.com/siyuan-note/siyuan/blob/v3.8.4/app/src/util/Tree.ts#L133
https://github.com/siyuan-note/siyuan/blob/v3.8.4/app/src/util/Tree.ts#L194
https://github.com/siyuan-note/siyuan/blob/v3.8.4/kernel/model/render.go#L71-L76
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-928g-4hfq-qwvx
https://www.vulncheck.com/advisories/siyuan-through-3.8.4-stored-xss-via-heading-style-attribute