Kavanagh, 25, has been called up by coach Steve McCormack, and qualifies for Scotland through grandparentage.
He said: “The World Cup is something I’ve always wanted to do. To test myself against the best in the world is something I’m really looking forward to.
“Steve was the coach when I first came to Widnes and I have always kept in touch with him, and it is good to get back with him.
“We spoke last year about it, and I found out I could definitely qualify, so it went from there.”
Kavanagh had hoped to feature for Scotland in last season’s internationals, but missed most of 2012 with an achilles injury.
“I probably would have been able to play, but I wanted to get a couple of games under my belt with Widnes, so I didn’t risk it.
“We have put a decent squad together, a couple of the NRL players have dropped out, but I think we should do OK. We’ve got a good mix of young and experienced players.
“Hopefully we can get through the group stage and see how it goes from there.”
Kavanagh, who came through the academy ranks at Wigan, has been at Widnes since 2008, and made 25 appearances for the Vikings in 2012.