A cross-site scripting vulnerability in queryparser/termgenerator_internal.cc in Xapian xapian-core before 1.4.6 exists due to incomplete HTML escaping by Xapian::MSet::snippet().
https://usn.ubuntu.com/3709-1/
https://trac.xapian.org/wiki/SecurityFixes/2018-07-02
https://lists.xapian.org/pipermail/xapian-discuss/2018-July/009652.html