What are the changes of being infected with oral herpes through lipstick sharing if there seems to be no lesions on the lips?

Very low, not zero: HSV1 is transmitted by direct skin contact, e.g. kissing. The risk via lipstick is very low, especially without a visible oral herpes outbreak. Still, lipstick should never be shared between people. Although HSV transmission is unlikely, the risk isn't zero; and sharing is high risk to transmit colds, influenza, etc. Don't do it.