The Go project reports:
+++ +net/http: denial of service due to improper 100-continue handling
+The net/http HTTP/1.1 client mishandled the case where a + server responds to a request with an "Expect: 100-continue" + header with a non-informational (200 or higher) status. This + mishandling could leave a client connection in an invalid + state, where the next request sent on the connection will + fail.
+An attacker sending a request to a + net/http/httputil.ReverseProxy proxy can exploit this + mishandling to cause a denial of service by sending "Expect: + 100-continue" requests which elicit a non-informational + response from the backend. Each such request leaves the + proxy with an invalid connection, and causes one subsequent + request using that connection to fail.
+