Envoy Gateway: tar header size is trusted before validation, so one OCI Wasm layer crash-loops the controller

Impact

extractWasmPluginBinary allocates memory from the untrusted tar header h.Size before validating the entry name or the declared size, and the surrounding LimitReader only bounds bytes actually read from the stream. A PAX or GNU header declaring a multi-terabyte entry therefore triggers an allocation attempt per tar entry and an unrecoverable Go runtime out-of-memory abort. No registry allowlist exists, so a tenant permitted to create an EnvoyExtensionPolicy can point spec.wasm[].code.image.url at any registry the controller can reach. Because the custom resource persists, reconciliation restarts the crash and the shared controller loops: a single non-volumetric request produces a cluster-wide control-plane denial of service affecting every namespace. This is a separate code path from the gzip case in CVE-2026-53716 and is fixed by the same release.

Who can reach it

Any authenticated tenant with RBAC to create or edit an EnvoyExtensionPolicy, plus a crafted OCI or Docker image in a registry the controller can pull from.

What to do

Upgrade Envoy Gateway to 1.7.4 or 1.8.1 and restart the controller deployment. Before patching, limit EnvoyExtensionPolicy creation to trusted operators and constrain controller egress to known registries. Recovering a crash-looping controller requires deleting the offending custom resource.

References

Related entries

• Envoy Gateway: a SecurityPolicy on a TCPRoute without spec.authorization panics translation and stalls xDSCVE-2026-53719 · Envoy Gateway control plane (translateSecurityPolicyForRoute, SecurityPolicy on TCPRoute)Medium
• Submariner: IPsec pre-shared key stored unencrypted in the Submariner custom resourceCVE-2026-66781 · Submariner operator (Submariner CR, IPsec pre-shared key)Medium
• KubeSphere cluster-controller: Cluster CRD endpoint is fetched unvalidated, giving SSRF from the controller podCVE-2026-71208 · KubeSphere cluster-controller (Cluster CRD connection config, addCluster / Discovery.ServerVersion)Medium
• ECK operator: unvalidated secret reference lets a namespace-scoped user read secrets from any namespaceCVE-2026-72640 · Elastic Cloud on Kubernetes (ECK) operator (secret reference reconciliation)Medium
• Elastic Cloud on Kubernetes: Fleet Server Elasticsearch token written into the workload spec in cleartextCVE-2026-72648 · Elastic Cloud on Kubernetes (ECK) operator - Fleet Server workload specMedium
• Dokploy: compose service names are interpolated into shell commands, giving command execution on the Docker hostCVE-2026-72739 · Dokploy (compose deployment createCommand shell interpolation)Medium