I want to use J/K trigger and I was told that usually IC outputs need pull-up resistor, but if I understand it correctly the following J/K trigger is based on CMOS: TI J/K trigger And it seems to me that CMOS is capable of making both low and high signal, so there is no need for pull-up resistor, right?
There is no need for a pull-up or pull-down resistor on CMOS outputs (unless they are open-drain). Inputs should always have a pull-up, pull-down or be connected a valid logic level (another output or a supply rail, usually).
The datasheet for the CD4027B does not indicate that the outputs are open-drain. Therefore no pull-up resistor to a DC power source is needed at the output.