Blazon: Argent a lion rampant sable holding in its paws a church gules
There are some visual similarities between the church in the arms and the city tower (built in 1384), but it is more likely that the choice of a church derives from the name of the town (“Kirsch” being German for church).
Kudos to Kirchberg for leaning into the canting arms connection rather than giving in to the temptation to depict any one of the numerous castles that existed nearby. Most of them are destroyed now, so we wouldn’t have known anyway, and I can always appreciate a good set of canting arms. (I really wish I could figure out where the lion comes from, though.)