Maintainers for mosquitto are Roger A. Light <firstname.lastname@example.org>.
You may want to refer to the following individual bug pages: libmosquitto-dev, libmosquitto0, libmosquitto0-dev, libmosquitto1, libmosquittopp-dev, libmosquittopp0, libmosquittopp0-dev, libmosquittopp1, mosquitto-clients, mosquitto-dbg, python-mosquitto, python3-mosquitto.
You might like to refer to the mosquitto package page, or to the Package Tracking System.
If you find a bug not listed here, please report it.