You should know that the DDR memory standards define just a handful of memory speed configurations that are "normal". Every stick of RAM has to support these standard modes, but they often get labelled as something like "3200 Mhz" or "4266 Mhz" in this case. This is actually a pre-programmed overclock in the stick that your motherboard can read and configure itself to.
The baseline speed for DDR4 is 2133 Mhz.
The 4266 Mhz mode is definitely an overclock. (At two times the normal speed! This is a gratuitous amount of overclocking TBH)
It will need to pull more voltage to be stable at that frequency.
That overclock is enabled through "XMP" or "DOCP" settings in the BIOS, but I would not recommend enabling that on this CPU.
Faster clock speeds on RAM do not simply translate to faster system performance. The bus speed is just one important factor, it only determines how often the CPU gets a chance to access RAM but the CPU does not utilize every bus cycle in the first place! It's like raising the speed limit on a highway but the cars driving on it still have a lower max speed.
Also with high clock speeds, the memory controller might even heat up enough to thermal throttle the cores in the CPU and negatively impact performance too.
My Recommendation:
I would suggest keeping the RAM frequency to a more modest speed like 3200 Mhz so it does not strain the CPU. 4266 Mhz is well beyond the point of diminishing returns for your money, and only going to provide noticeable improvements in benchmarks that don't represent realistic CPU & memory usage patterns.