CVE-2026-93923

HIGH 8.8

SiYuan through 3.8.4 Stored XSS via Heading Style Attribute

CVSS Score

8.8

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-79
Vendor	siyuan-note
Product	siyuan
Published	Sep 18, 2026

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CVSS v3 Breakdown

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

siyuan-note / siyuan

0 ≤ 3.8.4

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/siyuan-note/siyuan/security/advisories/GHSA-928g-4hfq-qwvx github.com: https://github.com/siyuan-note/siyuan github.com: https://github.com/siyuan-note/siyuan/blob/v3.8.4/kernel/model/render.go#L71-L76 github.com: https://github.com/siyuan-note/siyuan/blob/v3.8.4/app/src/util/Tree.ts#L133 github.com: https://github.com/siyuan-note/siyuan/blob/v3.8.4/app/src/util/Tree.ts#L194 vulncheck.com: https://www.vulncheck.com/advisories/siyuan-through-3.8.4-stored-xss-via-heading-style-attribute

Credits

EVIL0RD