Envoy is an open source edge and service proxy designed for cloud-native applications. Compliant HTTP/1 service should reject malformed request lines. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, There is a possibility that non compliant HTTP/1 service may allow malformed requests, potentially leading to a bypass of security policies. This issue is fixed in versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9.
https://www.rfc-editor.org/rfc/rfc9110#section-5.6.2
https://github.com/envoyproxy/envoy/security/advisories/GHSA-5jmv-cw9p-f9rp