FFmpeg versions 0.7.1 through 8.1.2 contain an out-of-bounds read vulnerability in the S/PDIF muxer that allows attackers to access memory beyond buffer boundaries by supplying a crafted DTS stream with a core_size value larger than the actual packet length. Attackers can exploit the missing bounds check in the spdif_header_dts4 function by providing a malicious DTS-HD audio stream during S/PDIF re-muxing to trigger unauthorized memory reads beyond the packet buffer.