CVE-2026-74800

critical · 9.4

SiYuan before v3.7.4 fails to set Content-Disposition and X-Content-Type-Options headers when serving arbitrary file assets, allowing stored cross-site scripting attacks. Authenticated attackers can upload HTML files as assets and execute scripts with full kernel API access when the workspace owner opens the asset link.

9.4

CVSS

0.4%

EPSS (exploit prob.)

35th

EPSS percentile

2026-08-17

Published

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Weaknesses

CWE-79

References

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-mjf3-jwmf-r6wf
https://www.vulncheck.com/advisories/siyuan-before-stored-xss-via-assets-endpoint

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-74800