There is a File Content Disclosure vulnerability in Action View <5.2.2.1, <5.1.6.2, <5.0.7.2, <4.2.11.1 and v3 where specially crafted accept headers can cause contents of arbitrary files on the target system’s filesystem to be exposed.
lists.opensuse.org/opensuse-security-announce/2019-05/msg00011.html
packetstormsecurity.com/files/152178/Rails-5.2.1-Arbitrary-File-Content-Disclosure.html
www.openwall.com/lists/oss-security/2019/03/22/1
access.redhat.com/errata/RHSA-2019:0796
access.redhat.com/errata/RHSA-2019:1147
access.redhat.com/errata/RHSA-2019:1149
access.redhat.com/errata/RHSA-2019:1289
groups.google.com/forum/#%21topic/rubyonrails-security/pFRKI96Sm8Q
lists.debian.org/debian-lts-announce/2019/03/msg00042.html
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y43636TH4D6T46IC6N2RQVJTRFJAAYGA/
weblog.rubyonrails.org/2019/3/13/Rails-4-2-5-1-5-1-6-2-have-been-released/
www.exploit-db.com/exploits/46585/