Crack along the stringer

Bought a used board and I'm guessing since it's already a bit of a beater, my first few sessions may have resulted in this crack along the stringer. I'm new to the sport and while I'm having a lot of fun learning words like stringer and ding repair, I'm a novice at this and am wondering how bad of a problem this is.
The guy who sold it to me said he does his own repairs and would be happy to show me now to fix it which is nice, I'm just wondering if this sort of crack will become a recurring issue? Is the board already compromised? Help!
The guy who sold it to me said he does his own repairs and would be happy to show me now to fix it which is nice, I'm just wondering if this sort of crack will become a recurring issue? Is the board already compromised? Help!