{"id":"CVE-2026-74800","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-74800","summary":"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…","details":"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.","published":"2026-08-17T11:16:40.187","modified":"2026-08-17T11:16:40.187","cvss":{"score":9,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":null,"references":[{"type":"WEB","url":"https://github.com/siyuan-note/siyuan/security/advisories/GHSA-mjf3-jwmf-r6wf"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/siyuan-before-stored-xss-via-assets-endpoint"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-08-17T11:16:40.187"}}