The Cleveland Browns took some risk signing Kareem Hunt, at least in terms of public perception, but financially there is no risk, according to Mike Florio of ProFootballTalk:

While Hunt is on the Commissioner Exempt list, the Brown will be paying him while he’s not eligible to play only if his suspension under the Personal Conduct Policy isn’t finalized until the start of the regular season, which is highly unlikely. If/when the suspension is announced and appealed before Week One, the Browns won’t be paying Hunt while Hunt serves his suspension.

The NFL is reviewing a couple of incidents involving Hunt, and it's unclear how long he will be suspended. Nothing would really be that much of a surprise at this point. The league has shown time and time again that it doesn't really use past cases to decide on punishment, so it could be anywhere from just a few games to a year.

How long he is suspended for could decide how much longer the Browns have total control over him:

As it relates to Cleveland’s contractual rights, if Hunt appears in fewer than six games this season, he’ll continue to have only two years of service for free agency purposes, making him an exclusive-rights free agent (i.e., not a free agent) in 2020. That would allow the Browns to keep him for another year at the minimum salary. If he’s suspended for the full year, Hunt’s current contract will toll until 2020.

The NFL also usually likes to drag its feet on this type of situation, so don't be surprised if this drags well into the summer.