libavcodec/pthread_frame.c in FFmpeg before 5.1.2, as used in VLC and other products, leaves stale hwaccel state in worker threads, which allows attackers to trigger a use-after-free and execute arbitrary code in some circumstances (e.g., hardware re-initialization upon a mid-video SPS change when Direct3D11 is used).
A null pointer dereference issue was discovered in 'FFmpeg' in decode_main_header() function of libavformat/nutdec.c file. The flaw occurs because the function lacks check of the return value of avformat_new_stream() and triggers the null pointer dereference error, causing an application to crash.
An issue was discovered in the FFmpeg package, where vp3_decode_frame in libavcodec/vp3.c lacks check of the return value of av_malloc() and will cause a null pointer dereference, impacting availability.
Prior to ffmpeg version 4.3, the tty demuxer did not have a 'read_probe' function assigned to it. By crafting a legitimate "ffconcat" file that references an image, followed by a file the triggers the tty demuxer, the contents of the second file will be copied into the output file verbatim (as long as the `-vcodec copy` option is passed to ffmpeg).
In FFmpeg before 4.2, avcodec_open2 in libavcodec/utils.c allows a NULL pointer dereference and possibly unspecified other impact when there is no valid close function pointer.
FFmpeg through 4.2 has a "Conditional jump or move depends on uninitialised value" issue in h2645_parse because alloc_rbsp_buffer in libavcodec/h2645_parse.c mishandles rbsp_buffer.
aa_read_header in libavformat/aadec.c in FFmpeg before 3.2.14 and 4.x before 4.1.4 does not check for sscanf failure and consequently allows use of uninitialized variables.
FFmpeg before commit cced03dd667a5df6df8fd40d8de0bff477ee02e8 contains multiple out of array access vulnerabilities in the mms protocol that can result in attackers accessing out of bound data. This attack appear to be exploitable via network connectivity. This vulnerability appears to have been fixed in cced03dd667a5df6df8fd40d8de0bff477ee02e8 and later.