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.

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Attack Requirements None

User Interaction Passive

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact High

Subsequent System Integrity Impact High

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Changed

Confidentiality Impact High

Integrity Impact High

Availability Impact None

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
siyuan-note siyuan unaffected
Version Status Constraints
0 affected < 3.7.3
3.7.3 unaffected —

No data.

No data.

No data.

Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-99rq-75j6-5j9f cve-icon
https://www.vulncheck.com/advisories/siyuan-before-stored-and-reflected-xss-via-svg-sanitizer-bypass cve-icon
History

Mon, 27 Jul 2026 16:15:00 +0000

Type Values Removed Values Added
Description 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.
Title SiYuan before v3.7.3 Stored and Reflected XSS via SVG Sanitizer Bypass
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 8.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N'}

cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N'}

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-07-27T15:43:45.397Z

Reserved: 2026-07-26T12:22:34.139Z

Link: CVE-2026-66394

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses