CVE-2026-66394
HIGHSiYuan before v3.7.3 Stored and Reflected XSS via SVG Sanitizer Bypass
Title source: cnaDescription
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.
References (2)
Core 2
Core References
Vendor Advisory vendor-advisory
GitHub Security Advisory (GHSA-99rq-75j6-5j9f)
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-99rq-75j6-5j9f
Third Party Advisory third-party-advisory
VulnCheck Advisory: SiYuan before v3.7.3 Stored and Reflected XSS via SVG Sanitizer Bypass
https://www.vulncheck.com/advisories/siyuan-before-stored-and-reflected-xss-via-svg-sanitizer-bypass
Scores
CVSS v3
8.7
EPSS
0.0027
EPSS Percentile
18.7%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
partial
Details
CWE
CWE-79
Status
published
Products (2)
siyuan-note/siyuan
< 3.7.3
siyuan-note/siyuan
3.7.3
Published
Jul 27, 2026
Tracked Since
Jul 27, 2026