Hawk before 3.1.3 and 4.x before 4.1.1 allow remote attackers to cause a denial of service (CPU consumption or partial outage) via a long (1) header or (2) URI that is matched against an improper regular expression.
https://nodesecurity.io/advisories/77
https://github.com/hueniverse/hawk/issues/168
https://github.com/hueniverse/hawk/commit/0833f99ba64558525995a7e21d4093da1f3e15fa
https://bugzilla.redhat.com/show_bug.cgi?id=1309721