CVE-2026-53714

Envoy Gateway: xDS Control Plane Information Disclosure when Envoy Gateway operates in GatewayNamespaceMode

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Published Sep 14, 2026 CVSS 3.1 · 7.4 High EPSS < 1% KEV · Not listed
Description
Envoy Gateway is an open source project for managing Envoy Proxy as a standalone or Kubernetes-based application gateway. Prior to 1.7.4 and 1.8.1, the xDS gRPC server in GatewayNamespaceMode, configured through provider.kubernetes.deploy.type=GatewayNamespace, installs a JWT StreamInterceptor but no UnaryInterceptor, leaving every unary Fetch RPC unauthenticated. The streaming interceptor also authenticates only discoveryv3.DeltaDiscoveryRequest messages; a discoveryv3.DiscoveryRequest used by the State-of-the-World protocol fails the type assertion and returns success without JWT validation. Any pod that can reach port 18000 can use the unauthenticated unary or State-of-the-World paths to retrieve TLS private keys through StreamSecrets, all xDS resources through StreamAggregatedResources, backend endpoints through StreamClusters or StreamEndpoints, and routing configuration through StreamRoutes or StreamListeners. This issue is fixed in versions 1.7.4 and 1.8.1.

Analysis

AI-generated

Technical impact

The vulnerability arises when the Envoy Gateway xDS gRPC server is configured for GatewayNamespaceMode. The server installs a JWT StreamInterceptor but no UnaryInterceptor, leaving every unary Fetch RPC unauthenticated. The streaming interceptor authenticates only discoveryv3.DeltaDiscoveryRequest messages; a discoveryv3.DiscoveryRequest used by the State‑of‑the‑World protocol fails the type assertion and returns success without JWT validation. Any pod that can reach port 18000 can use these unprotected paths to retrieve TLS private keys through StreamSecrets, all xDS resources through StreamAggregatedResources, backend endpoints through StreamClusters or StreamEndpoints, and routing configuration through StreamRoutes or StreamListeners. This issue is fixed in versions 1.7.4 and 1.8.1.

Affected Systems

The affected software is the Envoy Gateway project from envoyproxy. Versions prior to 1.7.4 and 1.8.1 are impacted when configured with provider.kubernetes.deploy.type=GatewayNamespace. The vulnerability is not limited to a particular operating system but applies to any deployment of these versions in a Kubernetes or standalone environment where the gRPC server is exposed on port 18000.

Risk and Exploitability

The CVSS score of 7.4 classifies the vulnerability as high‑severity. The EPSS score is <1%, indicating a very low probability of exploitation, and the issue is not listed in the CISA KEV catalog. Attackers must be able to reach port 18000, meaning the risk is scoped to internal network or misconfigured exposed services. Once an attacker can reach the endpoint, the lack of authentication enables direct retrieval of sensitive keys and configuration data with no additional privileges.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Update Envoy Gateway to version 1.7.4 or later 1.8.1, which adds the missing UnaryInterceptor
  • If an upgrade is not immediately possible, change the provider.kubernetes.deploy.type setting so that GatewayNamespaceMode is disabled or replaced with a mode that enforces proper authentication on all RPCs
  • Restrict network access to port 18000 to only trusted management pods or network policies, preventing external or unintended pods from contacting the unsecured xDS server

Generated by OpenCVE AI on September 20, 2026 at 22:36 UTC.

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-22xc-xg2r-9j7v Envoy Gateway: xDS Control Plane Information Disclosure when operating in GatewayNamespaceMode
History
Type Values Removed Values Added
References
Metrics threat_severity

None

 threat_severity

Important
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}
Type Values Removed Values Added
First Time appeared Envoyproxy
Envoyproxy gateway
Vendors & Products Envoyproxy
Envoyproxy gateway
Type Values Removed Values Added
Description Envoy Gateway is an open source project for managing Envoy Proxy as a standalone or Kubernetes-based application gateway. Prior to 1.7.4 and 1.8.1, the xDS gRPC server in GatewayNamespaceMode, configured through provider.kubernetes.deploy.type=GatewayNamespace, installs a JWT StreamInterceptor but no UnaryInterceptor, leaving every unary Fetch RPC unauthenticated. The streaming interceptor also authenticates only discoveryv3.DeltaDiscoveryRequest messages; a discoveryv3.DiscoveryRequest used by the State-of-the-World protocol fails the type assertion and returns success without JWT validation. Any pod that can reach port 18000 can use the unauthenticated unary or State-of-the-World paths to retrieve TLS private keys through StreamSecrets, all xDS resources through StreamAggregatedResources, backend endpoints through StreamClusters or StreamEndpoints, and routing configuration through StreamRoutes or StreamListeners. This issue is fixed in versions 1.7.4 and 1.8.1.
Title Envoy Gateway: xDS Control Plane Information Disclosure when Envoy Gateway operates in GatewayNamespaceMode
Weaknesses CWE-306
References
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N'}
Weaknesses
  • CWE-306

    Missing Authentication for Critical Function

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 15, 2026, 7:28 PM
Reserved
Jun 10, 2026, 4:43 PM

View source JSON

Updated
Sep 15, 2026, 7:28 PM

JSON

Status
Awaiting Analysis
Published
Sep 14, 2026, 9:17 PM
Modified
Sep 30, 2026, 5:43 PM

View source JSON

Severity
Important
Public date
Sep 14, 2026, 8:17 PM

View source Bugzilla JSON

Updated
Sep 20, 2026, 10:45 PM

JSON