BEEF validation answers valid for a raw entry that is not a transaction

Transaction::from_json holds an input txid that is not 64 hex digits and writes the input as spending the zero txid

Transaction readers accept trailing bytes, so a parsed transaction can carry another transaction id

Signature::from_der reads a signature with bytes after it, a wrong sequence length or an unneeded zero as the signature

Shamir backup recovery accepts a share at x = 0, so a supplied share can substitute the recovered private key