Our numerical simulations based on a single molecule, in line with the previous fully quantum-mechanical studies, reveal that the sharp resonance structure in the cavity frequency-dependent rate profile is the combined effect of energetic and kinetic constraints. The energetic constraint stipulates that the energy of a photon ω c should match the energy gap of a vibrational transition from state v mol k to the other state v mol k ′ . The height of the resonance peak at ω c = ∆ε mol k→k ′ is determined by kinetic factors, including the transition probability dictated by ⟨v mol k |µ(x)|v mol k ′ ⟩, the population probability, and the tunneling rate at these two vibrational states. When the cavity frequency is tuned to such a value, the cavity photon mode, along with the coupled cavity bath, induces vibrational heating in the reactant region and cooling in the product region. These pair of vibrational transitions, bridged by the tunneling in the vibrationally excited state, form a cavity-induced intramolecular cotunneling pathway. Depending on the interference of this reaction pathway with other reaction channels in the molecule, the rate is modified. In highly anharmonic systems, our study predicts the possibility of observing multiple resonance peaks, where the aforementioned kinetic factors corresponding to these vibrational transitions are not exponentially suppressed.