The Moped::BSON::ObjecId.legal? method in rubygem-moped before commit dd5a7c14b5d2e466f7875d079af71ad19774609b allows remote attackers to cause a denial of service (worker resource consumption) or perform a cross-site scripting (XSS) attack via a crafted string.
http://lists.fedoraproject.org/pipermail/package-announce/2015-July/161964.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-July/161987.html
https://bugzilla.redhat.com/show_bug.cgi?id=1229757