FFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in aribcaption_trans_text_subtitle() in libavcodec/libaribcaption.c when decoding with sub_type text. Attackers can supply a crafted ARIB STD-B24 caption stream with zero regions, causing a pointer write past a zero-sized sub->rects allocation and corrupting heap memory.
CWE-131