Some HTTP/2 implementations are vulnerable to ping floods, potentially leading to a denial of service. The attacker sends continual pings to an HTTP/2 peer, causing the peer to build an internal queue of responses. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both.
https://www.synology.com/security/advisory/Synology_SA_19_33
https://www.debian.org/security/2019/dsa-4520
https://www.debian.org/security/2019/dsa-4508
https://www.debian.org/security/2019/dsa-4503
https://usn.ubuntu.com/4308-1/
https://support.f5.com/csp/article/K98053339?utm_source=f5support&%3Butm_medium=RSS
https://support.f5.com/csp/article/K98053339
https://security.netapp.com/advisory/ntap-20190823-0005/
https://security.netapp.com/advisory/ntap-20190823-0004/
https://security.netapp.com/advisory/ntap-20190823-0001/
https://seclists.org/bugtraq/2019/Sep/18
https://seclists.org/bugtraq/2019/Aug/43
https://seclists.org/bugtraq/2019/Aug/31
https://seclists.org/bugtraq/2019/Aug/24
https://lists.debian.org/debian-lts-announce/2020/12/msg00011.html
https://kc.mcafee.com/corporate/index?page=content&id=SB10296
https://kb.cert.org/vuls/id/605641/
https://github.com/Netflix/security-bulletins/blob/master/advisories/third-party/2019-002.md
https://access.redhat.com/errata/RHSA-2020:0727
https://access.redhat.com/errata/RHSA-2020:0406
https://access.redhat.com/errata/RHSA-2019:4352
https://access.redhat.com/errata/RHSA-2019:4273
https://access.redhat.com/errata/RHSA-2019:4269
https://access.redhat.com/errata/RHSA-2019:4045
https://access.redhat.com/errata/RHSA-2019:4042
https://access.redhat.com/errata/RHSA-2019:4041
https://access.redhat.com/errata/RHSA-2019:4040
https://access.redhat.com/errata/RHSA-2019:4021
https://access.redhat.com/errata/RHSA-2019:4020
https://access.redhat.com/errata/RHSA-2019:4019
https://access.redhat.com/errata/RHSA-2019:4018
https://access.redhat.com/errata/RHSA-2019:3906
https://access.redhat.com/errata/RHSA-2019:3892
https://access.redhat.com/errata/RHSA-2019:3265
https://access.redhat.com/errata/RHSA-2019:3245
https://access.redhat.com/errata/RHSA-2019:3131
https://access.redhat.com/errata/RHSA-2019:2966
https://access.redhat.com/errata/RHSA-2019:2955
https://access.redhat.com/errata/RHSA-2019:2939
https://access.redhat.com/errata/RHSA-2019:2925
https://access.redhat.com/errata/RHSA-2019:2861
https://access.redhat.com/errata/RHSA-2019:2796
https://access.redhat.com/errata/RHSA-2019:2769
https://access.redhat.com/errata/RHSA-2019:2766
https://access.redhat.com/errata/RHSA-2019:2726
https://access.redhat.com/errata/RHSA-2019:2690
https://access.redhat.com/errata/RHSA-2019:2682
https://access.redhat.com/errata/RHSA-2019:2661
https://access.redhat.com/errata/RHSA-2019:2594
http://www.openwall.com/lists/oss-security/2019/08/20/1
http://seclists.org/fulldisclosure/2019/Aug/16
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00038.html
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00032.html
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00031.html
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00021.html
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00011.html
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00002.html
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00076.html