In Wireshark 2.6.0 to 2.6.1, 2.4.0 to 2.4.7, and 2.2.0 to 2.2.15, dissectors that support zlib decompression could crash. This was addressed in epan/tvbuff_zlib.c by rejecting negative lengths to avoid a buffer over-read.
http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00027.html
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=14675
https://lists.debian.org/debian-lts-announce/2018/07/msg00045.html