tcpdump 4.9.0 allows remote attackers to cause a denial of service (heap-based buffer over-read and application crash) via crafted packet data. The crash occurs in the EXTRACT_16BITS function, called from the stp_print function for the Spanning Tree Protocol.
https://support.apple.com/HT208221
https://security.gentoo.org/glsa/201709-23
https://bugzilla.redhat.com/show_bug.cgi?id=1468504