A stored cross-site scripting vulnerability in SiYuan allows authenticated attackers to execute malicious scripts with full kernel access when a workspace owner interacts with a crafted asset link.

The application fails to implement proper Content-Disposition and X-Content-Type-Options headers, enabling an authenticated attacker to upload malicious HTML files that execute upon access.

Successful exploitation poses a severe risk to organizational data integrity and confidentiality. Given the CVSS score of 9.0, this vulnerability permits full compromise of the application environment, potentially leading to unauthorized data exfiltration or administrative account takeover by an attacker who has gained initial access to the platform.

Immediate Action: Upgrade the SiYuan installation to version 3.7.4 or later to implement the required security header enforcement.

Proactive Monitoring: Audit application access logs for unusual file uploads or frequent requests to asset endpoints that deviate from typical user behavior.

Compensating Controls: Implement strict Content Security Policy (CSP) headers at the web server level to restrict the execution of untrusted scripts if immediate patching is not feasible.

Public Exploit Available: No (exploit_available: unknown)

The critical nature of this vulnerability necessitates an immediate update to the patched version. Security administrators should prioritize this deployment to prevent potential lateral movement or data theft within the workspace environment.