Cal. Penal Code § 1170.89

Where there is an applicable triad for an enhancement related to the possession of, being armed with, use of, or furnishing or supplying a firearm, set forth in Section 12021.5, 12022, 12022.2, 12022.3, 12022.4, 12022.5, or 12022.55 the fact that a person knew or had reason to believe that a firearm was stolen shall constitute a circumstance in aggravation of the enhancement justifying imposition of the upper term on that enhancement.