The Cardholder Authentication Verification Value (CAVV) is the authentication value merchants obtain after a successful 3D Secure authentication. For security reasons, Adyen is required to check the validity of the authentication value and ensure it's not re-used in any context. 

The specific reason for decline varies, for example, when the authorization transaction amount differs from the authentication amount. You can see a particular reason for the CAVV decline in your Customer Area.

Â