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.
https://aws.amazon.com/security/security-bulletins/2026-055-aws/
https://github.com/kubernetes-sigs/aws-load-balancer-controller/releases/tag/v3.4.2
Published: 2026-07-14
Updated: 2026-07-15
Base Score: 7.1
Vector: CVSS2#AV:N/AC:H/Au:S/C:C/I:C/A:C
Severity: High
Base Score: 8.5
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Severity: High
Base Score: 5.8
Vector: 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
Severity: Medium
EPSS: 0.00373