Move the leather item outdoors or to a well-ventilated area
Wear gloves and a mask
Brush off loose mold with a soft dry brush
Wipe the surface with a dry microfiber cloth
Mix equal parts white vinegar and water
Lightly dampen a cloth with the solution
Wipe the moldy areas gently
Do not soak the leather
Wipe again with a clean damp cloth
Dry the leather with a towel
Let the item air-dry completely away from direct heat or sunlight
Apply a leather conditioner after drying
Repeat if needed
Test any cleaning solution on a hidden spot first
If mold is severe or deeply embedded, seek professional cleaning