CVE-2026-53717

Vulnerability report without repro case. Repro case may be added later after harness is complete. **Preconditions (4):** - Tenant can create EnvoyExtensionPolicy (baseline) - Controller has egress to attacker-controlled OCI registry - No registry allowlist (none exists in code) - Layer presents Docker/OCI media type **Description** At imagefetcher.go:287, make([]byte, h.Size) uses the attacker-controlled tar-header size; the LimitReader at :278 bounds bytes read from the stream but not the header-declared size returned by tr.Next() (a 512-byte header can claim a multi-TB entry via PAX/GNU encoding). Reached from untrusted tenant input via EnvoyExtensionPolicy spec.wasm[].code.image.url (envoyextensionpolicy.go:1157 → cache.go:262/299 → imagefetcher.go:218 → :287), and the allocation happens for every tar entry regardless of filename. The resulting Go runtime OOM throw is unrecoverable and, because the CRD persists, crash-loops the shared controller — single-request, non-volumetric, cluster-wide DoS.

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, internal/wasm/imagefetcher.go follows tenant-controlled EnvoyExtensionPolicy spec.wasm[].code.image.url values to Docker or OCI Wasm layers, and extractWasmPluginBinary uses the untrusted tar-header h.Size value to allocate memory before validating the entry name or declared size. A small PAX or GNU tar header can therefore claim a multi-terabyte entry even though the surrounding LimitReader restricts only the bytes read from the stream, and no registry allowlist prevents a permitted tenant from selecting an attacker-controlled registry that the controller can reach. The allocation is attempted for every tar entry and can cause an unrecoverable Go runtime out-of-memory failure; because the custom resource persists, reconciliation repeatedly crash-loops the shared controller and causes a single-request, non-volumetric, cluster-wide control-plane denial of service. This issue is fixed in versions 1.7.4 and 1.8.1.

Envoy Gateway: OCI layer extraction allocates make([]byte, h.Size) from untrusted tar header in github.com/envoyproxy/gateway