** DISPUTED ** A stack-based buffer overflow in the subtitle decoder in Libav 12.3 allows attackers to corrupt the stack via a crafted video file in Matroska format, because srt_to_ass in libavcodec/srtdec.c misuses snprintf. NOTE: Third parties dispute that this is a vulnerability because “no evidence of a vulnerability is provided” and only “a generic warning from a static code analysis” is provided.