Question about future of the Voyager probes and Pioneer 10?

Quick question here - Voyager I and II, along with Pioneer 10, were sent off on missions to the other planets, which they've long ped. I was thinking about at their limited speed how long it'd take them to make it to another star system. Then I got to thinking - are they still bound by the Sun's gravity? Rather than ever leaving the solar system, are they simply going to fall back inward and establish an elliptical orbit? Thanks.