Thanks. Let us know.

I noticed it hours ago, so I haven't do some experiments about it.
But after I close WinSCP and restart with the same SSH connection configuration, only one port is bounded now.
My usage is usual. Only operations are changing/refreshing local/remote working directories in explorer view and uploading/downloading files (cancelled sometimes).
I think the problem comes from time. I use WinSCP in my working environment, so the connection will be kept for weeks until my local machine has to close.
I also met the same problem months ago, but I didn't check it with netstat.
Status of these ports are all "bound" but not listening or in a connection. It looks like something like memory leak.
I will keep observing ports in following days.

martin wrote:

Thanks for you report.
Can you tall what operation causes an additional port to be bound?
Are you using some unusual settings? Like SSH tunneling?

Thanks for you report.
Can you tall what operation causes an additional port to be bound?
Are you using some unusual settings? Like SSH tunneling?

shows nearly all ports between 1000 and 15000 are bounded by WinSCP.
This makes my application can't listen on these ports.
What happened here?

WinSCP version: I just updated it after I closed it, so I don't know the issue version.
OS version: Windows Server 2016 DataCenter
Protocol: SFTP
GUI or command: GUI explorer
Reproduction: keep WinSCP connected to a remote SSH server for weeks and do a lot of file transfers