Traefik: `allowCrossNamespace=false` bypass via `@kubernetescrd` TraefikService backendRef

Summary There is a medium severity vulnerability in Traefik's Kubernetes CRD provider. When providers.kubernetesCRD.allowCrossNamespace is disabled — the default — cross-namespace @kubernetescrd references are rejected for middlewares, TLS options and HTTP/TCP ServersTransports, but the same...

CVE-2026-71325

Traefik exposes a cross-namespace bypass for TraefikService backends via @kubernetescrd references. The CVE affects Traefik’s Kubernetes CRD service resolver: when the reference name contains an @kubernetescrd, the resolver’s guard for cross-namespace references is not enforced for TraefikService...

Traefik CRD IngressRouteTCP ServersTransport Cross-Provider Namespace Bypass

Summary There is a medium-severity cross-provider reference vulnerability in Traefik's Kubernetes CRD provider. The crossProviderNamespaces allowlist is enforced for HTTP serversTransport references but was not enforced for IngressRouteTCP service serversTransport references. A low-privileged...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization in the createChainMiddleware function. Even when providers.kubernetesCRD.allowCrossNamespace=false is set, references in spec.chain.middlewares may be followed to access objects in other namespaces. A user with...

Allocation of Resources Without Limits or Throttling

Overview Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling due to unbounded processing of responses in the ForwardAuth middleware due to the lack of restrictions for maxResponseBodySize configuration. An attacker can cause resource exhaustion...

Allocation of Resources Without Limits or Throttling

Overview Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling due to unbounded processing of responses in the ForwardAuth middleware due to the lack of restrictions for maxResponseBodySize configuration. An attacker can cause resource exhaustion...

This Week in Spring - June 6th, 2023

Hi, Spring fans! Welcome to another installment of This Week in Spring! And what an insane week it's been! Long story short, I've spent 10-12 hours a day over the last five days migrating a dozen differnet applications and services from one GKE cluster to another, taking the time to update things...