get active userform in class module

the following code create three userforms, each one containing a commandbutton defined in a class module and, when clicked on an userform, it should cycle over all controls of that userform. How can I understand on which userform the user has clicked the commandbutton? I don't know if there is a simple solution or it can be done for example using API functions.

this is the code in the userform named Userform1 (add the commandbutton to the userform):

Private Sub UserForm_initialize()

    Dim cb_class As Class_CmdButton
    Dim cb_cmd As MSForms.CommandButton
    
    Set cb_cmd = Me.Controls.Add("forms.commandbutton.1", "CommandButton1")
    cb_cmd.Move 50, 50, 120, 30
    Set cb_class = New Class_CmdButton
    Set cb_class.CmdButton = cb_cmd
    CDict.Add cb_class, cb_cmd

End Sub

this is the code in a standard module (create the userforms):

Sub openuserform()

Dim MyUF As Object
Dim MyUFname As String

Set CDict = CreateObject("Scripting.dictionary")

For i = 1 To 3
    Set MyUF = ActiveWorkbook.VBProject.VBComponents.Add(vbext_ct_MSForm)
    MyUFname = MyUF.Name
    VBA.UserForms.Add (MyUFname)
    Set MyUF = New UserForm1
    MyUF.Show vbModeless
Next

End Sub

and this is the code in the class module named Class_CmdButton (where i have the problem)

Private WithEvents CMB As MSForms.CommandButton

Private ctrl As Control
Private UF As UserForm

Public Property Set CmdButton(ByVal cmd As MSForms.CommandButton)
    Set CMB = cmd
    CMB.Caption = "Caption CmdButton"
End Property

Private Sub CMB_Click()

    Set UF= 'HOW CAN I GET ACTIVE USERFORM?
    For Each ctrl In UF.Controls
        MsgBox F.Caption, ctrl.Name
    Next

End Sub

thanks in advance for your help

Sorry for my late answer, .parent works perfectly, i've also tried to use a property but should i use .parent also in this case to reference the form? It's not completely clear to me how to handle the property in this case
thanks