CVE-2026-15738

Cross-namespace traffic interception via incorrect route precedence ordering in AWS Load Balancer Controller

State: Published
Severity: 5.8 Medium
Published: Jul 14, 2026
Updated: Jul 15, 2026
Reserved: Jul 14, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
4.0	5.8 Medium	CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H	AMZN
3.1	8.5 High	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H	AMZN

Weaknesses

CWE-653 Improper isolation or compartmentalization

Affected Products

Product	Versions
aws-load-balancer-controllerAmazon	before 3.4.2Affected

References

https://github.com/kubernetes-sigs/aws-load-balancer-controller/releases/tag/v3.4.2release-notes
https://aws.amazon.com/security/security-bulletins/2026-055-aws/vendor-advisory

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