Only if you've set up port forwards on your router sending certain ports to your Sonos speakers, or have your Sonos speaker in your router's "DMZ", or have set up firewall rules allowing incoming connections to be made to your Sonos speakers from the internet.
Considering only around 5,000 Sonos speakers worldwide, out of millions sold, are connected to networks with poor security settings, doesn't mean this is a major issue. So no, you don't likely need to worry about that.
However, it's always a good time to look at your router/firewall settings and make sure that everything is set up as you might expect it to be. This also includes looking at the UPnP service that many routers have to make it easier for devices or programs to set up a port forward without any involvement by you.
The S in IOT stands for Security.