CVE-2026-112778
Awaiting Analysis Awaiting Analysis - Queue

Traefik Kubernetes Ingress Namespace Validation Bypass

Publication date: 2026-10-19

Last updated on: 2026-10-19

Assigner: VulnCheck

Description
Traefik before 2.11.46, 3.x before 3.6.17, and 3.7.0 lack namespace validation for Ingress and Service annotations in the Kubernetes Ingress provider, allowing references to Middlewares, ServersTransports, and TLSOptions in other namespaces. Attackers able to create or update Ingress or Service resources in one namespace can set router.middlewares or service.serverstransport annotations to obtain another tenant's injected credentials or reuse its client certificates, bypassing namespace-based tenant isolation.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-10-19
Last Modified
2026-10-19
Generated
2026-10-20
AI Q&A
2026-10-19
EPSS Evaluated
N/A
NVD
CVE-2026-112778
EUVD
EUVD-2026-104584

Affected Vendors & Products

Showing 3 associated CPEs
Vendor Product Version / Range
traefik traefik 0
traefik traefik 3.0.0
traefik traefik 3.7.0

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-862 The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This vulnerability in Traefik's Kubernetes Ingress provider allows attackers to bypass namespace-based tenant isolation by referencing Middlewares, ServersTransports, and TLSOptions from other namespaces through annotations. This occurs because the provider does not validate namespace restrictions in annotations, unlike the CRD provider which enforces them via the allowCrossNamespace option.

Detection Guidance

Check Traefik versions for affected releases (up to v2.11.45, v3.6.16, v3.7.0). Review Kubernetes Ingress and Service resources for annotations like router.middlewares or service.serverstransport referencing resources in other namespaces. Use kubectl get ingress -A -o yaml to inspect annotations across all namespaces.

Impact Analysis

Attackers with permissions to create or modify Ingress or Service resources in one namespace can steal sensitive data like credentials or client certificates from other namespaces. They can also bypass authentication mechanisms such as mTLS, gaining unauthorized access to protected services.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, violating data protection requirements under GDPR and HIPAA. It undermines tenant isolation, potentially exposing personal or health information to unauthorized parties, resulting in compliance breaches.

Mitigation Strategies

Upgrade Traefik to patched versions (v2.11.46, v3.6.17, v3.7.1). Configure the crossProviderNamespaces option to restrict cross-namespace references. Audit and remove any suspicious annotations in Ingress and Service resources that reference resources outside their namespace.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-112778. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart