The Apache HTTP Server 2.4.17 and 2.4.18, when mod_http2 is enabled, does not limit the number of simultaneous stream workers for a single HTTP/2 connection, which allows remote attackers to cause a denial of service (stream-processing outage) via modified flow-control windows.
https://security.netapp.com/advisory/ntap-20180601-0001/
https://security.gentoo.org/glsa/201610-02
https://access.redhat.com/errata/RHSA-2017:1161
http://www.securityfocus.com/bid/92331
http://www.oracle.com/technetwork/topics/security/bulletinoct2016-3090566.html
http://www.oracle.com/technetwork/security-advisory/cpuoct2016-2881722.html
http://www.apache.org/dist/httpd/CHANGES_2.4