Some HTTP/2 implementations is 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.
net/http in Go before 1.15.12 and 1.16.x before 1.16.4 allows remote attackers to cause a denial of service (panic) via a large header to ReadRequest or ReadResponse. Server, Transport, and Client can each be affected in some configurations.
Some HTTP/2 implementations is vulnerable to a reset flood, potentially leading to a denial of service. The attacker opens a number of streams and sends an invalid request over each stream that should solicit a stream of RST_STREAM frames from the peer. Depending on how the peer queues the RST_STREAM frames, this can consume excess memory, CPU, or both.