You want to determine which GuiXT version is delivered with a specific version of SAP GUI.
Solution
Click on "Software Downloads" on the SAP Support Portal, search for "SAP GUI" and open the "Maintenance Software Component"
part. Click on the icon in the "Related Info" column. You will receive a list with various corrections. GuiXT may be included several times in this list, so look for the most recent entry.
Components
GuiXT