Rubber composites excel in industrial and consumer applications due to their high deformability, tear resistance, and damping. However, they are susceptible to aging from environmental factors like oxygen, ozone, temperature, and weathering, even during storage. The mechanistic understanding of fracture through fractographic analysis was conducted on the 50 phr carbon black filled natural rubber/butadiene rubber composites subjected to storage aging at ambient conditions (20–28 °C and 55–90% RH) for three years. Fracture strength decreased by 37% after three years, from 15.77 ± 0.58 MPa to 10.01 ± 0.41 MPa. Fractographic analysis revealed a “cup-and-cone” fracture origin, indicative of shear yielding, followed by the formation of distinct fractures, namely smooth zone, hackle marks, and rupture zone combined with a dimpled fracture morphology indicative of particulate-filler debonding from the rubber matrix. Aging shifted the fracture origin away from the edge, reduced the smooth zone radius from 2.28 ± 0.19 mm to 1.32 ± 0.22 mm, and decreased fracture energy from 61.26 ± 4.06 J to 28.48 ± 3.22 J. This is attributed to environmental aging, causing chain scission and crosslink rupture, as evidenced by reduced crosslink density from 0.4564 ± 0.0261 to 0.3256 ± 0.0141 mol/cm3 and elongation at break from 883 ± 41% to 624 ± 57%. Results demonstrate that environmental aging significantly degrades the mechanical properties and fracture resistance of rubber composites, evidenced by a shift in fracture initiation and a reduction in the smooth zone radii.