The PIMv2 parser in tcpdump before 4.9.2 has a buffer over-read in print-pim.c:pimv2_print().
https://support.apple.com/HT208221
https://security.gentoo.org/glsa/201709-23
https://github.com/the-tcpdump-group/tcpdump/commit/6fca58f5f9c96749a575f52e20598ad43f5bdf30
https://access.redhat.com/errata/RHEA-2018:0705
http://www.tcpdump.org/tcpdump-changes.txt