CVE-2026-85594
Critical
9.8 CVSS v3.1
CVSS v4.0: 7.0
- Published
- Sep 4, 2026
- Updated
- Oct 8, 2026
- Vendor
- Traefik
- Affected versions
- See affected products
- Weakness
- CWE-639
Summary
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.
Severity
Critical (9.8)CVSS 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Affected products
- Traefik Traefik < 3.7.11
Exploitation status
Unknown
Technical details
Technical analysis has not been written for this record yet.
Mitigation & remediation
Follow the vendor advisory linked below for patches and workarounds.