Scales to Play Over Cm
Every chord is a subset of several scales: any scale that contains all of a chord's tones fits over it. Pick a chord to see the matching scales from its own root, the major keys the chord belongs to, and full fretboard diagrams for every scale on guitar.
A Cm chord contains the notes C – D# – G. Any scale that includes every one of those 3 tones fits over it — from the root C, that means C Natural Minor, C Melodic Minor, C Harmonic Minor, C Minor Pentatonic, C Blues, C Rock 'n' Roll, C Dorian, C Phrygian, C Dorian Bebop, C Half Whole Diminished, C Gypsy Major and C Gypsy Minor. Start with the first scale listed: it is the most common choice, and the others color the same chord tones differently.
Cm is also diatonic to 3 major keys: A# major (relative minor Gm), D# major (relative minor Cm), G# major (relative minor Fm). In a song from one of those keys you can also solo with the key's own major scale or its relative minor pentatonic across the whole progression, not just this chord.