Is it possible to edit Credit Card field data?

No. GravityView intentionally prevents editing Credit Card fields. The Edit Entry screen blocks the field from being shown, and Gravity Forms only stores masked values (card type and last four digits). For security and PCI compliance, the full card number and CVV are never stored, so there’s nothing to edit.

If you need to change payment details, update them in the payment gateway or have the user submit a new entry/payment.