CVE-2026-85594CWE-639

CVE-2026-85594

Critical · published September 4, 2026

CVSS v3.1
9.8
EPSS
0%
Percentile
40.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
7.0 · 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
EPSS
0.00477 · 40.2th percentile
Weakness
CWE-639 · Authorization Bypass Through User-Controlled Key
Published
2026-09-04T16:17Z
Affected products (1)
ProductVersionsFixed in
traefik/traefik< 3.7.113.7.11
References (2)
https://github.com/traefik/traefik/security/advisories/GHSA-m6wx-622r-48r9 · [email protected]https://www.vulncheck.com/advisories/traefik-3.7.1-crossprovidernamespaces-bypass-via-service-middleware · [email protected]
EPSS history
Timeline
  • 06 SEP 03:33Z
    EPSS moved — → 0%
    epss
  • 04 SEP 11:29Z
    Traefik v3.7.1 crossProviderNamespaces Bypass via Service Middleware
    cvelistv5