CVE-2019-5737

An attacker can cause a Denial of Service (DoS) by establishing an HTTP or HTTPS connection in keep-alive mode and by sending headers very slowly thereby keeping the connection and associated resources alive for a long period of time. Attack potential is mitigated by the use of a load balancer or other proxy layer. This vulnerability is an extension of CVE-2018-12121, addressed in November and impacts all active release lines including 6, 8, 10 and 11.
Source: NIST
CVE-2019-5737