EUVD-2026-78072
GHSA-fcrp-7gc2-93g7
Severity by source
AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L
PR:L reflects required HTTPRoute write rights; AC:H reflects extension-managed custom backendRef precondition; C:H for unauthorized cross-namespace backend access; S:U as scope remains within the Envoy Gateway deployment.
Primary rating from Vendor (https://github.com/envoyproxy/gateway).
CVSS VectorVendor: https://github.com/envoyproxy/gateway
Lifecycle Timeline
2DescriptionCVE.org
Impact
Envoy Gateway accepts extension-managed custom backendRefs from an HTTPRoute to a backend resource in another namespace without requiring a matching Gateway API ReferenceGrant in the target namespace. This breaks the Gateway API cross-namespace consent model: the namespace that owns the referenced backend resource does not need to opt in with a ReferenceGrant before another namespace’s HTTPRoute can use that resource.
Patches
AnalysisAI
Cross-namespace authorization bypass in Envoy Gateway allows an authenticated user with HTTPRoute creation rights to route traffic to backend resources in foreign namespaces without the required Gateway API ReferenceGrant consent from the target namespace owner. Affected versions span all releases before 1.7.4 and the 1.8.x line before 1.8.1. The flaw is specific to extension-managed custom backendRefs: standard Gateway API backendRefs are not affected, but when extensions introduce custom backend resource types, the ReferenceGrant enforcement gate is skipped entirely, violating the multi-tenant isolation guarantee the Gateway API cross-namespace model is designed to provide. No public exploit or CISA KEV listing exists at time of analysis.
Technical ContextAI
Envoy Gateway is a Kubernetes-native implementation of the Gateway API specification, built on top of Envoy Proxy. The Gateway API cross-namespace reference model mandates that any HTTPRoute in namespace A pointing to a backend in namespace B must be accompanied by a ReferenceGrant resource in namespace B that explicitly opts in to that reference - this is the consent mechanism protecting namespace-level tenancy boundaries. CWE-862 (Missing Authorization) describes the root cause: the Envoy Gateway control plane performs ReferenceGrant validation for standard backendRefs but omits equivalent validation for extension-managed custom backendRef types. CPE data identifies the vulnerable Go module as pkg:go/github.com/envoyproxy/gateway, with two distinct vulnerable ranges: all versions below 1.7.4, and versions from 1.8.0-rc.0 up to but not including 1.8.1.
RemediationAI
The primary remediation is upgrading Envoy Gateway to version 1.7.4 (for 1.7.x deployments) or 1.8.1 (for 1.8.x deployments), available at https://github.com/envoyproxy/gateway/releases/tag/v1.7.4 and https://github.com/envoyproxy/gateway/releases/tag/v1.8.1 respectively. If patching is not immediately possible, a targeted compensating control is to audit and restrict which principals hold HTTPRoute create/update permissions (via Kubernetes RBAC) to only fully trusted tenants - this prevents untrusted namespace operators from crafting malicious cross-namespace backendRefs. A second compensating control is to disable or withhold deployment of any Envoy Gateway extensions that introduce custom backendRef types until the patch is applied, since the bypass only affects extension-managed custom backendRefs; environments using exclusively standard backendRefs are not exposed. Note that restricting RBAC access may impact legitimate multi-tenant self-service workflows and should be assessed against operational requirements before applying.
Same weakness CWE-862 – Missing Authorization
View allSame technique Authentication Bypass
View allVendor StatusVendor
SUSE
Severity: Moderate| Product | Status |
|---|---|
| SUSE Linux Enterprise Server 16.1 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Affected |
| SUSE Linux Enterprise Module for Package Hub 15 SP5 | Affected |
| SUSE Linux Enterprise Module for Package Hub 15 SP6 | Affected |
| openSUSE Leap 15.5 | Affected |
| openSUSE Leap 15.6 | Affected |
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External POC / Exploit Code
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