You can export markers in Adobe Audition CC as shown below. CS6 and older versions do not appear to have the ability to export or import markers.
Select the markers you want to export (Ctrl+A for all), right-click an empty area of the markers panel and click "Export Selected Markers". It will export it as a tab-delimited CSV file.
You can also import markers as well using the "Import Markers from File" option.