Envoy version 1.14.2, 1.13.2, 1.12.4 or earlier may exhaust file descriptors and/or memory when accepting too many connections.
https://www.envoyproxy.io/docs/envoy/v1.13.1/intro/version_history
https://github.com/envoyproxy/envoy/security/advisories/GHSA-v8q7-fq78-4997