CVE-2026-85594: traefik traefik

CVSS 9.8 (critical) · published 2026-09-04

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.

Affected products (NVD): traefik traefik

Fixed in (NVD): 3.7.11

Weakness: CWE-639

Source: NVD CVE-2026-85594

References

• https://github.com/traefik/traefik/security/advisories/GHSA-m6wx-622r-48r9
• https://www.vulncheck.com/advisories/traefik-3.7.1-crossprovidernamespaces-bypass-via-service-middleware

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