I had a black spot in my vaulted master bedroom ceiling. Darn. Used a borescope to poke through and look up there. Near a vent pipe. Darn. Poked one of my fiberglass electric "fish" poles through to mark the spot and get all the way through the insulation. So there are scissor trusses up there to create the vaulted ceiling. At 69 I crawled up there and moving sheets of plywood ahead of me so I could get to the location. Sure enough, bad glue joint (not the first bad or nonexistent glue joint I found in this year 2000 built house). I can barely reach the spot. Good excuse to buy a 12 volt milwaukee sawzall (18 volt one was too heavy to hold at arm's length). So I cut out the bad stuff, have all my tools and glue, etc. up there and make the repair. Getting out of there was tough...Can't recall if I had to back out or manage to turn around. I have a respirator on. Naturally I spill the glue! What a mess and I'm in a rush to get out. At the juncture to the non-vaulted area, (mind you, glue is all over me on my shirt and I'm rushing!) I slip and don't want to step through the ceiling below so I stop my fall on my ribs to one of the truss 2x4's. Darn that hurt! Never had bruised ribs before but it hurt for a solid month! And darn, I still had to repair the ceiling I was trying to avoid ruining.
So, yeah, vent pipes can leak. It's just as important to do a good job gluing them as with water supply and DWV pipes.