Is CVE-2026-53718 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-53718 being exploited in the wild.

How severe is CVE-2026-53718?

Medium severity, with a CVSS score of 6.4, published 14 September 2026.

Which products and versions are affected?

github.com/envoyproxy/gateway (Go) SEMVER:introduced=0,fixed=1.7.4,introduced=1.8.0-rc.0,fixed=1.8.1, SEMVER:introduced=1.8.0-rc.0,fixed=1.8.1.

Is there a fix for CVE-2026-53718?

Yes. github.com/envoyproxy/gateway (Go): upgrade to 1.8.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-53718 attacked?

It is attacked over the network, in a hosted service.

Am I affected by CVE-2026-53718?

Check whether you run github.com/envoyproxy/gateway (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-53718: Envoy Gateway ReferenceGrant bypass in custom backendRef

CVE-2026-53718 · Severity: medium · CVSS 6.4 · Published 2026-09-14

Envoy Gateway, a tool used to manage network traffic for applications, contains a security flaw in how it handles cross-namespace traffic. An attacker with limited access could bypass security boundaries to connect to backend resources in different administrative areas without the required permission from the resource owner. This could lead to unauthorized access to sensitive internal services or data.

Technologies: github.com/envoyproxy/gateway (Go). Vendors: Go.

Quick answers

Is CVE-2026-53718 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-53718 being exploited in the wild.
How severe is CVE-2026-53718?: Medium severity, with a CVSS score of 6.4, published 14 September 2026.
Which products and versions are affected?: github.com/envoyproxy/gateway (Go) SEMVER:introduced=0,fixed=1.7.4,introduced=1.8.0-rc.0,fixed=1.8.1, SEMVER:introduced=1.8.0-rc.0,fixed=1.8.1.
Is there a fix for CVE-2026-53718?: Yes. github.com/envoyproxy/gateway (Go): upgrade to 1.8.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-53718 attacked?: It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-53718?: Check whether you run github.com/envoyproxy/gateway (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

github.com/envoyproxy/gateway (Go): upgrade to 1.8.1 or later
```
go get github.com/envoyproxy/gateway@v1.8.1
```

Technical details

Envoy Gateway is vulnerable to a missing authorization check (CWE-862) when processing extension-managed custom backendRefs in HTTPRoutes. The software fails to verify the existence of a Gateway API ReferenceGrant in the target namespace, which is required to authorize cross-namespace references. An attacker with the ability to create HTTPRoutes in one namespace can reference and potentially interact with backend resources in another namespace without the owner's consent. This bypasses the standard Gateway API security model for cross-namespace resource sharing. The issue is fixed in versions 1.7.4 and 1.8.1.

Affected products

Envoy Proxy Gateway < 1.7.4, >= 1.8.0-rc.0, < 1.8.1

Identifiers

CVE-2026-53718
GHSA-fcrp-7gc2-93g7
GO-2026-6007

Timeline

2026-06-05: disclosed
2026-07-16: advisory: GitHub Advisory published

References

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