Vulnerability · Published Aug 17, 2026 · Assigned by VulnCheck
CVE-2026-74800SiYuan before v3.7.4 Stored XSS via assets endpoint
Critical 9.0
In plain English
A critical-severity cross-site scripting in siyuan from siyuan-note. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities).
Severity (CVSS 3.1)9.0Critical
Exploit odds (30 days)0.4%top 62.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| siyuan-note | siyuan | 0 – before 3.7.4 |
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
References
- GitHub Security Advisory (GHSA-mjf3-jwmf-r6wf) vendor-advisory
- VulnCheck Advisory: SiYuan before v3.7.4 Stored XSS via assets endpoint third-party-advisory