CVE-2026-74902
SiYuan before v3.7.4 XSS-to-RCE via malicious filename upload
- State
- Published
- Severity
- 9.3 Critical
- Published
- Aug 18, 2026
- Updated
- Oct 8, 2026
- Reserved
- Aug 17, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 9.3 Critical | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H | VulnCheck |
| 3.1 | 8.6 High | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H | VulnCheck |
Weaknesses
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Products
| Product | Versions |
|---|---|
siyuansiyuan-note |
|
References
- GitHub Security Advisory (GHSA-jf56-jrhq-j2qp)vendor-advisory
- VulnCheck Advisory: SiYuan before v3.7.4 XSS-to-RCE via malicious filename uploadthird-party-advisory
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.