Bug 2529861 (CVE-2026-85594)

Summary: CVE-2026-85594 github.com/traefik/traefik: Traefik: Information disclosure via crossProviderNamespaces bypass in Kubernetes Ingress provider
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: anjoseph, jprabhak, sdawley, wtam
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Traefik. The software fails to enforce `crossProviderNamespaces` restrictions on the `traefik.ingress.kubernetes.io/service.middlewares` Service annotation within the Kubernetes Ingress provider. This vulnerability allows a namespace-limited tenant, even if excluded from the allowlist, to attach an operator-owned middleware to its Service. If this middleware injects backend credentials, the tenant can then recover these credentials at a controlled backend, leading to information disclosure.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-09-08 14:59:17 UTC
Traefik versions from v3.7.1 fail to enforce crossProviderNamespaces restrictions on the traefik.ingress.kubernetes.io/service.middlewares Service annotation in the Kubernetes Ingress provider. A namespace-limited tenant excluded from the allowlist can attach an operator-owned middleware to its Service, and if that middleware injects backend credentials, recover them at a controlled backend.