The Core CPI print ( 0.2% MoM vs 0.3% exp, 2.9% YoY) matches the official BLS release for May. No evidence it's fabricated.
BLS methodology has longstanding issues though — OER shelter smoothing, substitutions, and quality adjustments often make official inflation look milder than what many households experience on housing, food, and services. This one was slightly soft on core but energy spiked. Take the number at face value with those caveats.