FFmpeg 8.1 through 9.0.2 contains a denial of service vulnerability in the lcevc_metadata bitstream filter caused by a process block position mismatch in lcevc_metadata_handle_vui(). Attackers can supply crafted LCEVC access units with two IDR or non-IDR NAL units to trigger an av_assert0 failure in ff_cbs_lcevc_list_add(), aborting the application.