CVE-2026-15738 Cross-namespace traffic interception via incorrect route precedence ordering in AWS Load Balancer Controller
An authenticated user can intercept, spoof, or deny gRPC traffic from other namespaces by exploiting incorrect route precedence in the AWS Load Balancer Controller.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-15738?
CVE-2026-15738 is a medium-severity missing authorization vulnerability in Amazon aws-load-balancer-controller, published on 14 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-653
Which versions are affected by CVE-2026-15738?
How do I fix CVE-2026-15738?
No fix has been published for CVE-2026-15738 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-15738 being exploited?
There is no known exploitation of CVE-2026-15738 in the wild and no public exploit code.