CVE-2026-54761 Details
Description
Traefik is an HTTP reverse proxy and load balancer. Prior to 3.6.21 and 3.7.5, there is a high severity vulnerability in Traefik's Kubernetes Gateway provider affecting the crossProviderNamespaces allowlist. For HTTPRoute rules that declare multiple (WRR) backendRefs, Traefik evaluates the allowlist against the target backendRef.namespace instead of the route's own namespace. As a result, an HTTPRoute created in a namespace that is not allow-listed can reference a cross-provider TraefikService such as api@internal, dashboard@internal or rest@internal by pointing backendRef.namespace at an allow-listed namespace covered by a Gateway API ReferenceGrant, exposing internal Traefik services on the data plane. Exploitation requires the ability to create an accepted HTTPRoute and a matching ReferenceGrant from an allow-listed namespace; it does not require any change to Traefik static configuration, RBAC, or the deployment itself. This vulnerability is fixed in 3.6.21 and 3.7.5.
A high-severity vulnerability exists in Traefik's Kubernetes Gateway provider, specifically in versions prior to 3.6.21 and 3.7.5. The issue involves a bypass of the crossProviderNamespaces allowlist. For HTTPRoute rules that specify multiple backendRefs, Traefik incorrectly checks the allowlist against the backendRef.namespace instead of the route's own namespace. This flaw allows an HTTPRoute in a non-allowlisted namespace to reference cross-provider TraefikServices, such as api@internal, dashboard@internal, or rest@internal, by directing backendRef.namespace to an allowlisted namespace with a Gateway API ReferenceGrant. Consequently, internal Traefik services can be exposed on the data plane. Exploitation requires creating an accepted HTTPRoute and a corresponding ReferenceGrant from an allowlisted namespace, without needing to modify Traefik's static configuration, RBAC, or the deployment itself.
Users can upgrade to Traefik versions 3.6.21 or 3.7.5 to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 25, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/traefik/traefik/releases/tag/v3.6.21 | [email protected] | Release NotesPatch |
| https://github.com/traefik/traefik/releases/tag/v3.7.5 | [email protected] | Release NotesPatch |
| https://github.com/traefik/traefik/security/advisories/GHSA-3g6v-2r68-prfc | [email protected] | ExploitMitigationPatchVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-284 | Improper Access Control | [email protected] |
| CWE-863 | Incorrect Authorization | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| traefik traefik | < 3.6.21 >= 3.7.0, < 3.7.5 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 26, 2026 | Initial Analysis | [email protected] |
| Jun 25, 2026 | CVE Modified | CISA-ADP |
| Jun 23, 2026 | New CVE Received | [email protected] |