The Amatrice-Visso-Norcia seismic sequence struck Central Italy across the Apenninic normal faults system in 2016. Fluids likely triggered the sequence and reduced the stability of the fault network following the first earthquake (Amatrice, M_w6.0), with their migration nucleating the Visso (M_w5.9) and Norcia (M_w6.5) mainshocks. However, both spatial extent and mechanisms of fluid migration and diffusion through the network remain unclear. High fluid content, enhanced permeability and pervasive microcracking increase seismic attenuation, but each process contributes to different attenuation mechanisms. Here, we measured and mapped peak delay time and late-time coda attenuation, using them as proxies of seismic scattering and absorption before and during the sequence. Structural discontinuities and lithology control scattering losses at all frequencies, with the highest scattering delineating carbonate formations within the Gran Sasso massif. The Monti Sibillini thrust marks the strongest contrasts in scattering, indicating a barrier for northward fracture propagation. Before the sequence, low-frequency high-absorption anomalies distribute around the chain axis. A single high-absorption anomaly bounded north by the Monti Sibillini thrust develops NNW-SSE across the seismogenic zone during the sequence. This spatial expansion appears related to the deep migration of CO₂-bearing fluids across the strike of the fault network from a deep source of trapped CO₂ near the Amatrice earthquake. Migration develops primarily during the Visso sequence, followed by diffusion across the fault zones during the Norcia sequence. High-scattering and high-absorption focus below the carbonates south of Norcia during the sequence, mapping the progressive northern permeation of the seismogenic zone from south to north.