CVE-2026-74800 — CRITICAL (9.0)

Vulnerability 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.

CVSS Score

9.0

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

REQUIRED

Scope

CHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Related Weaknesses (CWE)

CWE-79

References

FAQ

What is CVE-2026-74800?

CVE-2026-74800 is a vulnerability with a CVSS score of 9.0 (CRITICAL). 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 u...

How severe is CVE-2026-74800?

CVE-2026-74800 has been rated CRITICAL with a CVSS base score of 9.0/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2026-74800?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.