My wife's Honda CRV makes humming sound from back.

What is your question?

She noticed it when she went to the back to take something out of the cargo area. Could this be from an exhaust leak? If so is it dangerous to drive? She's two hours from home. The car seems to drive perfectly fine on the short trips she's taken since noticing the sound.

What makes this problem better or worse?

Not sure

How long has your 2010 Honda CR-V had this problem?

One day