The PostgreSQL JDBC Driver has a SQL injection vulnerability when using the PreferQueryMode=SIMPLE connection property. This allows an attacker to inject SQL and alter queries, bypassing protections against SQL injection attacks. The vulnerability requires specific conditions to be met, including a placeholder for a numeric value immediately preceded by a minus and a second placeholder for a string value on the same line. Both parameters must be user-controlled. The vulnerability can be exploited to expose assets and has a high impact on confidentiality, integrity, and availability.