Its possible to build a crystal oscillator using an odd number of inverters chained together - for highish frequencies 1 might do, lower frequencies might need 3 or 5. Also probably need load capacitors too, and some experimentation (sometimes a crystal will run at a harmonic).
So if you've a spare invertor (or NOR/NAND) gate hanging around...
BTW a 20MHz oscilloscope will see 26MHz signal, it will be attenuated somewhat.