An issue was discovered in zlib_decompress_extra in modules/demux/mkv/util.cpp in VideoLAN VLC media player 3.x through 3.0.7. The Matroska demuxer, while parsing a malformed MKV file type, has a double free.
https://usn.ubuntu.com/4074-1/
https://security.gentoo.org/glsa/201908-23
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00081.html
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00040.html
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00037.html
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00005.html