The updated glib2.0 packages fix security vulnerabilities:
In GNOME GLib 2.56.1, gmarkupparsecontextend_parse() in gmarkup.c has a NULL pointer dereference (CVE-2018-16428).
GNOME GLib 2.56.1 has an out-of-bounds read vulnerability in gmarkupparsecontextparse() in gmarkup.c, related to utf8_str() (CVE-2018-16429).