CVE-2026-66394

HIGH SEVERITY

CVSS Score & Metrics

Base Score

8.7 / 10

Vector String

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

Vulnerability 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.

Vulnerability Details

Published Date

July 27, 2026

Last Modified

July 27, 2026

CWE ID

CWE-79

Source

NVD

Vendor

siyuan-note

Product

siyuan

External References

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

CVE-2026-66394

CVSS Score & Metrics

Vulnerability Description

Vulnerability Details

External References

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