Agno version 2.6.5 contains a critical SQL injection vulnerability in its ClickHouse vector database backend. The vulnerability exists in the delete_by_metadata() method where attackers can inject arbitrary SQL expressions through malicious metadata keys and values. The root cause is unsafe f-string interpolation in clickhousedb.py file. This vulnerability allows attackers to perform various malicious activities including deleting all database rows, targeting specific rows for deletion, or extracting sensitive information through error-based or blind SQL injection techniques. The vulnerability has been documented with associated GitHub issues and pull requests for remediation.