Vulnerability · Published Oct 19, 2026 · Assigned by VulnCheck

CVE-2026-112778Traefik before 2.11.46, 3.6.17, and 3.7.1 Cross-Namespace Resource Reference via Kubernetes Annotations

Medium 6.4

In plain English

A medium-severity missing authorization in traefik from traefik. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities).

Severity (CVSS 4.0)6.4Medium

Exploit odds (30 days)0.2%top 89.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
traefik	traefik	0 – before 2.11.46
traefik	traefik	3.0.0 – before 3.6.17
traefik	traefik	3.7.0 – before 3.7.1

Weakness: CWE-862 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:H

References

GitHub Security Advisory (GHSA-rh7m-2m44-x32f) vendor-advisory
VulnCheck Advisory: Traefik before 2.11.46, 3.6.17, and 3.7.1 Cross-Namespace Resource Reference via Kubernetes Annotations third-party-advisory