by Kastro
Paper/Archive/CVE-2026-74902

CVE-2026-74902

siyuan-note siyuan — SiYuan before v3.7.4 XSS-to-RCE via malicious filename upload

EPSS 0.2%CVSS 9.3
critical.is priorityof 100
30
CVSS 9.3 (CNA)9.3 / 10 × 3027.9Not in CISA KEV+300.0EPSS percentile 9.6.096 × 201.9No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
siyuan< 3.7.43.7.4CNA

Scores by source

VulnCheck (CNA)9.3CVSS: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 (CNA)8.6CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

advisorygithub.com/siyuan-note/siyuan/security/advisories/GHSA-jf56-jrhq-j2qpwriteupvulncheck.com/advisories/siyuan-before-xss-to-rce-via-malicious-filename-upload