SiYuan is a personal knowledge management system. Prior to version 3.1.16, SiYuan's `/api/template/renderSprig` endpoint is vulnerable to Server-Side Template Injection (SSTI) through the Sprig template engine. Although the engine has limitations, it allows attackers to access environment variables. Version 3.1.16 contains a patch for the issue.
CWE-1336, CWE-94