Travis Barker's Blink-182 Concert Attended By Ghostlike Person, Maybe Kourtney

Big mystery in Montreal over the weekend at a Blink 182 concert ... someone enveloped in a blanket is getting special attention from one Travis Barker, and lots of folks suspect it's Kourtney Kardashian!

The ghostlike figure sat underneath the blanket for the entire concert. At times the person was moving around as if they were uncomfortable ... it was super hot in the venue.

So here's the clue. When the concert was over, Travis hopped off stage, wrapped his arm around the mystery person and walked off.

Now if this were some rando, you'd think security might step in and check out what's what, but that apparently didn't happen ... further evidence it's Kourtney.

Blink's really on a roll since Coachella.  They're now in the midst of their world tour. They perform in Toronto Monday.