Medium severity · published Jan 16, 2026
CVE-2026-23645
SiYuan Vulnerable to Stored Cross-Site Scripting (XSS) via Unrestricted SVG File Upload
6.1
CVSS
0.3%
EPSS
No
On KEV
Description
SiYuan is self-hosted, open source personal knowledge management software. Prior to 3.5.4-dev2, a Stored Cross-Site Scripting (XSS) vulnerability exists in SiYuan Note. The application does not sanitize uploaded SVG files. If a user uploads and views a malicious SVG file (e.g., imported from an untrusted source), arbitrary JavaScript code is executed in the context of their authenticated session. This vulnerability is fixed in 3.5.4-dev2.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 20% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SI
siyuan · siyuan-note
< 3.5.4-dev2 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-23645
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-23645
Patch
https://github.com/siyuan-note/siyuan/commit/11115da3d0de950593ee4ce375cf7f9018484388
Issue Tracking
https://github.com/siyuan-note/siyuan/issues/16844
Exploit
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-pcjq-j3mq-jv5j
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