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 unsafe f-string interpolation in clickhousedb.py allows attackers to inject arbitrary SQL expressions through malicious metadata keys and values. Attackers can exploit this flaw to delete all rows, target specific data, or extract sensitive information using error-based or blind SQL injection techniques. The vulnerability affects the vector database functionality and poses significant risks to data integrity and confidentiality.