The net/http library in net/textproto/reader.go in Go before 1.4.3 does not properly parse HTTP header keys, which allows remote attackers to conduct HTTP request smuggling attacks via a space instead of a hyphen, as demonstrated by "Content Length" instead of "Content-Length."
https://github.com/golang/go/commit/117ddcb83d7f42d6aa72241240af99ded81118e9
https://bugzilla.redhat.com/show_bug.cgi?id=1250352
http://www.securityfocus.com/bid/76281
http://seclists.org/oss-sec/2015/q3/294
http://seclists.org/oss-sec/2015/q3/292
http://seclists.org/oss-sec/2015/q3/237
http://rhn.redhat.com/errata/RHSA-2016-1538.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-October/168029.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-October/167997.html