knative.dev/pkg admission webhooks allow unbounded request-body memory exhaustion

⚠️ Update verification, 2026-05-19: C-2 confirmed end-to-end — 4.5× amplification observed worse than the advisory's conservative 2× claim Built a Go PoC cmd/poc-c2/main.go that runs the exact 8-line vulnerable snippet from webhook/admission.go:109-117 verbatim under the same http.HandlerFunc shap...