GNOME GLib 2.56.1 has an out-of-bounds read vulnerability in g_markup_parse_context_parse() in gmarkup.c, related to utf8_str().
https://usn.ubuntu.com/3767-2/
https://usn.ubuntu.com/3767-1/
https://lists.debian.org/debian-lts-announce/2019/07/msg00029.html
https://gitlab.gnome.org/GNOME/glib/issues/1361
https://gitlab.gnome.org/GNOME/glib/commit/cec71705406f0b2790422f0c1aa0ff3b4b464b1b