High severity · published Aug 18, 2026
CVE-2026-74902
SiYuan before v3.7.4 XSS-to-RCE via malicious filename upload
8.6
CVSS
0.2%
EPSS
No
On KEV
Description
SiYuan before v3.7.4 contains a cross-site scripting vulnerability in the file upload validation flow that fails to escape filenames before inserting them into HTML via insertAdjacentHTML. Attackers can craft a malicious filename containing script payloads that execute with full OS command access when a user drags, drops, or pastes the file into the editor.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 9% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SI
siyuan · siyuan-note
before 3.7.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-74902
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-74902
vendor-advisory
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-jf56-jrhq-j2qp
third-party-advisory
https://www.vulncheck.com/advisories/siyuan-before-xss-to-rce-via-malicious-filename-upload
More from siyuan
10.0
CVE-2026-72811
SiYuan before v3.7.4 SQL Injection via backlink search
10.0
CVE-2026-69085
SiYuan before v3.7.3 SQL Injection via searchDocs
10.0
CVE-2026-69084
SiYuan before v3.7.3 SQL Injection via searchEmbedBlock
10.0
CVE-2026-69083
SiYuan before v3.7.3 SQL Injection via fullTextSearchAssetContent
10.0
CVE-2026-66012
SiYuan before v3.7.2 Unauthenticated Administrator Takeover via MCP