Is it permissible to give an ongoing charity (ṣadaqa jāriya) on behalf of one's parents while they are still alive, without their knowledge?

Ongoing charity on behalf of parents is a good deed whose reward reaches them. The parents' permission is not a prerequisite for giving charity on their behalf. However, it is not permissible for the charity to be from their money without their permission, because that is disposing of another's property without their permission, which is forbidden.