Envoy Gateway custom backendRef cross-namespace ReferenceGrant bypass
CVE-2026-53718
MEDIUMPre-NVD 6.46.4
EchelonGraph scoreLOW confidence
This medium-severity CVE scores 6.4 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: cna:github_m
6.4
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: —CVSS: 6.4Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.4
- EG Score
- 6.4(low)
- EG Risk
- 33(Track)EG Risk 33/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity64% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- —
- KEV
- Not listed
Published
July 16, 2026
Last Modified
July 16, 2026
Vendor Advisories for CVE-2026-53718(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
Go(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| github.com/envoyproxy/gateway | — | 1.8.1 | — |
Data Freshness Timeline
(refreshed 1× in last 7d / 2× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-23 03:19 UTCEG score recompute
- 2026-07-16 20:05 UTCEG score recompute
Frequently asked(4)
What is CVE-2026-53718?
CVE-2026-53718 is a medium vulnerability published on July 16, 2026. Envoy Gateway custom backendRef cross-namespace ReferenceGrant bypass 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…
When was CVE-2026-53718 disclosed?
CVE-2026-53718 was first published in the National Vulnerability Database on July 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-53718?
CVE-2026-53718 has a CVSS v4.0 base score of 6.4 (CNA self-assessment; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-53718?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-53718, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-53718
Is Your Infrastructure Affected by CVE-2026-53718?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.