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CWE-653Weakness · CWE-653

CVE-2026-15738

HIGH · 8.5 CVSS v3.1 Published 2026-07-14
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
91/100
Remediation priority · Urgent
Remotely reachable Zero-click 6 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Incorrect behavior order in the Gateway API listener-rule generation in Amazon AWS Load Balancer Controller before 3.4.2 might allow an authenticated remote user to intercept, spoof, or deny another namespace's gRPC traffic on a shared Gateway via a crafted HTTPRoute resource. To mitigate this issue, users should upgrade to version 3.4.2.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The AWS Load Balancer Controller before version 3.4.2 has an incorrect behavior order in Gateway API listener-rule generation. When multiple HTTPRoute resources across different namespaces target a shared Gateway, the rule ordering logic allows an authenticated user to craft a malicious HTTPRoute that intercepts, spoofs, or denies gRPC traffic destined for routes in other namespaces by manipulating listener priority and rule precedence.

MitigationUpgrade AWS Load Balancer Controller to version 3.4.2 or later. Review existing HTTPRoute resources in the cluster for any unauthorized or unexpected rules that may have been created, and ensure proper RBAC policies limit who can create Gateway API resources.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify AWS Load Balancer Controller version
    Run 'kubectl get deployment -n kube-system aws-load-balancer-controller -o jsonpath="{.spec.template.spec.containers[0].image}"' or check Helm release with 'helm list -n kube-system' and 'helm get values <release> -n kube-system'
    Affected if The version is before 3.4.2 (e.g., 3.4.1, 3.4.0, earlier)
  2. List all HTTPRoute resources in the cluster
    Run 'kubectl get httproute --all-namespaces -o wide' to see which HTTPRoutes exist and which Gateway they reference
    Affected if Multiple HTTPRoutes across different namespaces reference the same Gateway listener
  3. Inspect Gateway listener configuration
    Run 'kubectl get gateway <gateway-name> -n <namespace> -o yaml' and examine the listener spec and attached route names, noting the order in which HTTPRoutes are attached
    Affected if Listeners show HTTPRoutes from multiple namespaces with no explicit precedence rules defined
  4. Check for unexpected or suspicious route rules
    Describe or get the HTTPRoute resources with 'kubectl describe httproute <name> -n <namespace>' and review hostnames, matches, and filters for anomalous patterns that could intercept other namespace traffic
    Affected if Any HTTPRoute has overly broad hostnames or path matches that could overlap with routes in other namespaces, or shows unexpected priority values

A user is affected if the AWS Load Balancer Controller version is below 3.4.2 AND multiple HTTPRoute resources from different namespaces target the same Gateway, allowing rule precedence manipulation.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade AWS Load Balancer Controller to version 3.4.2 or later. Review existing HTTPRoute resources in the cluster for any unauthorized or unexpected rules that may have been created, and ensure proper RBAC policies limit who can create Gateway API resources.

Recommended fix High confidence

3.4.2

  1. 1. Identify the namespace where the AWS Load Balancer Controller is deployed (typically 'kube-system' or 'aws-load-balancer-controller').
  2. 2. Check the current installed version of the controller using: helm list -n <namespace> or kubectl get deployment -n <namespace> -o wide
  3. 3. If using Helm, upgrade the AWS Load Balancer Controller to version 3.4.2 using: helm upgrade <release-name> aws-load-balancer-controller/aws-load-balancer-controller --version 3.4.2 -n <namespace>
  4. 4. If using a manifest-based deployment, apply the updated manifest for version 3.4.2 from the AWS Load Balancer Controller GitHub releases.
  5. 5. Verify the upgrade was successful by checking the controller pod is running and the new version is deployed: kubectl get deployment -n <namespace> -o jsonpath='{.items[*].spec.template.spec.containers[*].image}'
  6. 6. Ensure Gateway API resources (GRPCRoute, HTTPRoute) continue to function correctly after the upgrade.

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing3.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,570
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-15738 in production — separate from our analysis above.

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