CVE-2025-9039

Summary
Amazon Elastic Container Service (Amazon ECS) is a fully managed container orchestration service that enables customers to deploy, manage, and scale containerized applications. Amazon ECS container agent provides an introspection API that provides information about the overall state of the Amazon ECS agent and the container instances.

We identified CVE-2025-9039, an issue in the Amazon ECS agent.

Impact
Under certain conditions, this issue could allow an introspection server to be accessed off-host by another instance if the instances are in the same security group or if their security groups allow incoming connections that include the port where the server is hosted. This issue does not affect instances where the option to allow off-host access to the introspection server is set to 'false'.

Impacted versions: version 0.0.3 through 1.97.0

Patches
This issue has been addressed in ECS agent version 1.97.1. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.

Workarounds
Customers who cannot update to the latest AMI can modify the Amazon EC2 security groups to restrict incoming access to the introspection server port (51678).

References
If you have any questions or comments about this advisory, we ask that you contact AWS Security via our vulnerability reporting page or directly via email to [email protected]. Please do not create a public GitHub issue.

CVE-2025-9039 has a CVSS score of 4.3 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.97.1); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2025-9039? CVE-2025-9039 is a medium-severity security vulnerability in github.com/aws/amazon-ecs-agent (go), affecting versions >= 0.0.3, <= 1.97.0. It is fixed in 1.97.1.
2. How severe is CVE-2025-9039? CVE-2025-9039 has a CVSS score of 4.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/aws/amazon-ecs-agent are affected by CVE-2025-9039? github.com/aws/amazon-ecs-agent (go) versions >= 0.0.3, <= 1.97.0 is affected.
4. Is there a fix for CVE-2025-9039? Yes. CVE-2025-9039 is fixed in 1.97.1. Upgrade to this version or later.
5. Is CVE-2025-9039 exploitable, and should I be worried? Whether CVE-2025-9039 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2025-9039 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2025-9039? Upgrade github.com/aws/amazon-ecs-agent to 1.97.1 or later.