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.
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Fixes

Solution

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Workaround

No workaround given by the vendor.

History

Wed, 16 Sep 2026 21:00:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N'}

cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}


Sat, 12 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1220
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N'}

threat_severity

Important


Tue, 08 Sep 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 04 Sep 2026 11:45:00 +0000

Type Values Removed Values Added
Description 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.
Title Traefik v3.7.1 crossProviderNamespaces Bypass via Service Middleware
First Time appeared Traefik
Traefik traefik
Weaknesses CWE-639
CPEs cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*
Vendors & Products Traefik
Traefik traefik
References
Metrics cvssV4_0

{'score': 7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-08T15:51:47.581Z

Reserved: 2026-09-04T10:59:00.162Z

Link: CVE-2026-85594

cve-icon Vulnrichment

Updated: 2026-09-08T14:47:33.626Z

cve-icon NVD

Status : Analyzed

Published: 2026-09-04T12:17:22.830

Modified: 2026-10-08T16:17:55.383

Link: CVE-2026-85594

cve-icon Redhat

Severity : Important

Publid Date: 2026-09-04T11:29:58Z

Links: CVE-2026-85594 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-21T06:30:09Z

Weaknesses