This study was published in January 2021 in the Journal of Affective Disorders and it found that OCD patients who used CBD through inhalation saw significant short-term improvement in many common symptoms. The study included 87 subjects and spanned well over two years (31 months).
"Patients reported a 60% reduction in compulsions, a 49% reduction in intrusions, and a 52% reduction in anxiety from before to after inhaling cannabis. Higher concentrations of CBD and higher doses predicted larger reductions in compulsions."
There was some "accommodation" effect (increased tolerance) over time. There are several other studies that have linked CBD to improvement in OCD symptoms and their links are in a nice summary article from greenentrepreneur.com.