Venality is the quality of being open to bribery or overly motivated by money. A government worker's venality might lead him to exchange state secrets for cash.
Criminals are known for their venality, being willing to break the law for a financial reward. This kind of venality can vary from police officers accepting bribes to politicians making decisions and passing laws based on campaign contributions. The Late Latin root word is venalitatem, "capable of being bought," from venum, "for sale."