Medium · published September 15, 2026
Envoy Gateway is an open source project for managing Envoy Proxy as a standalone or Kubernetes-based application gateway. Prior to 1.7.4 and 1.8.1, HTTPServer.ServeHTTP in internal/wasm/httpserver.go reads the plain mappingPath2Cache map without synchronization while HTTPServer.Get writes the same map during EnvoyExtensionPolicy translation. An attacker with pod-network access to unauthenticated port 18002 and tenant permission to churn policies with distinct Wasm URLs can flood GET requests until a per-request reader overlaps a writer. Go's concurrent map read and write detection invokes runtime.throw, which the net/http connection recovery cannot catch, terminating the controller process and causing a timing-dependent, cross-tenant control-plane denial of service until Kubernetes restarts the pod. This issue is fixed in versions 1.7.4 and 1.8.1.