Small cut on a leather sofa seat - any ideas how to fix it?

Could you buy a matching patch that may not look great but at least it will stop the split getting bigger ?

Maybe an old fashion cobbler would know how to repair leather or at least someone who works in leather, maybe a saddle maker?? Try googling for someone in your area. Good luck.

There are leather specialists who will professionally repair leather furniture
We had our leather chair (accidentally torn by DGS and a push along toy) successfully repaired.
It involved an invisible repair and then
re-dying the area.
All in all we very satisfied with the repair.

We had insurance taken out when we purchased the suite.
Not sure if house insurance would cover it.

Thank you all for your suggestions. After posting, I did a search on leather repairs and found some specialist leather glue with dark material to put underneath the slit to hold it in place. I ordered it so here's hoping it will do the trick at not much cost.