Breadboard Power Supplies' Output Voltage Incorrect
These supplies use LDO voltage regulators (1117) - maximum dropout is only about 0.8V according to the datasheet, so they can operate as low as 6ish volts.  In general, yes, linear regulators require more voltage but LDO's have a much smaller difference in voltage differential between the input and output.
Also, these regulators are limited to a maximum of 16 Volts in.
I have also seen where the output voltages are mislabeled - the 3.3V puts out 5V.  I would always check these with a meter before plugging into a breadboard.
Also, not too hard to repair - I was able to replace the regulators by clipping the leads and just heating up the top tab.