CVE-2026-74902CWE-79cross-site-scripting

CVE-2026-74902

High · published August 18, 2026

CVSS v3.1
8.6
EPSS
0%
Percentile
9.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.6 · HIGH
Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CVSS v4.0
9.3 · 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
EPSS
0.00198 · 9.1th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-08-18T16:19Z
References (2)
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-jf56-jrhq-j2qp · [email protected]https://www.vulncheck.com/advisories/siyuan-before-xss-to-rce-via-malicious-filename-upload · [email protected]
EPSS history
Timeline
  • 18 AUG 11:19Z
    SiYuan before v3.7.4 XSS-to-RCE via malicious filename upload
    cvelistv5