FFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in ff_dxva2_hevc_fill_picture_parameters() that allows attackers to corrupt memory via unbounded non-uniform tile counts. Attackers can supply crafted HEVC bitstreams with many non-uniformly spaced tiles to write controlled 16-bit values past fixed-size DXVA arrays during DXVA2, D3D11VA, or D3D12VA decoding on Windows.