The agroot() function in cgraph\obj.c in libcgraph.a in Graphviz 2.39.20160612.1140 has a NULL pointer dereference, as demonstrated by graphml2gv.
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2019-11023.json"
[ { "events": [ { "introduced": "0" }, { "last_affected": "2.39.20160612.1140" } ] } ]