CVE-2026-53718
Envoy Gateway custom backendRef cross-namespace ReferenceGrant bypass
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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, 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.
Timeline
ID reserved
By GitHub_M
- 3 months later
· 3 months later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium6.4 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L |
| NVDNVD · Awaiting Analysis | 3.1 | Medium6.4 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L |
- EPSS (exploitation in 30 days)
- 0.41% · top 64% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.4.
Weakness
Affected products
- affected < 1.7.4
- affected >= 1.8.0-rc.0, < 1.8.1
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/envoyproxy/gatewayGHSA-fcrp-7gc2-93g7 (opens in a new tab)
References (9)
- https://github.com/envoyproxy/gateway/security/advisories/GHSA-fcrp-7gc2-93g7 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/envoyproxy/gateway/pull/9171 (opens in a new tab)x_refsource_MISC
- https://github.com/envoyproxy/gateway/pull/9172 (opens in a new tab)x_refsource_MISC
- https://github.com/envoyproxy/gateway/pull/9173 (opens in a new tab)x_refsource_MISC
- https://github.com/envoyproxy/gateway/commit/5a78db82b7cf4fc5bebbeda2c50952892038a464 (opens in a new tab)x_refsource_MISC
- https://github.com/envoyproxy/gateway/commit/96e2b750868a459ace4b8b68e6a6e4fb0152b9b7 (opens in a new tab)x_refsource_MISC
- https://github.com/envoyproxy/gateway/commit/b4737180c7e597490c6363075c565fa8cf24eead (opens in a new tab)x_refsource_MISC
- https://github.com/envoyproxy/gateway/releases/tag/v1.7.4 (opens in a new tab)x_refsource_MISC
- https://github.com/envoyproxy/gateway/releases/tag/v1.8.1 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-fcrp-7gc2-93g7 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-53718)Record last updated .