CVE-2026-53718

What it is

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, an HTTPRoute can use an extension-managed custom backendRef to reference a backend resource in another namespace without a matching Gateway API ReferenceGrant in the target namespace. The custom-backend branch in internal/gatewayapi/route.go omits validateBackendNamespace, allowing the route-owning namespace to bind to and use the resource without the backend namespace owner's consent and violating the Gateway API cross-namespace authorization model. This issue is fixed in versions 1.7.4 and 1.8.1.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data exposure.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-09-14 21:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-25 14:10 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.4% in the next 30 days (EPSS).
• Severity: 6.4 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-09-14 21:17 UTC

Last modified

2026-09-25 14:10 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-862 · Missing authorization

Record status

Awaiting Analysis

Attack profile CVSS 3.1 · 6.4

Attack vector

Network

Complexity

High

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

Low

Availability

Low

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-53718.md and follow it. Check whether this project is affected by CVE-2026-53718. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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