Traefik v3.7.1 crossProviderNamespaces Bypass via Service Middleware
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.
CVE-2026-85594
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-85594
traefik
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "traefik",
"product": "traefik",
"versions": [
{
"status": "affected",
"version": "3.7.1",
"versionType": "semver",
"lessThanOrEqual": "3.7.12"
}
],
"packageURL": "pkg:golang/github.com/traefik/traefik/v3",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-85594
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #13005 · Revision 1
- Added to Heist Feed
- Publisher date