CVE-2026-24470
Ingress Controller ExternalName Misconfiguration Enables Unauthorized Internal Access
Publication date: 2026-01-26
Last updated on: 2026-02-18
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| zalando | skipper | to 0.24.0 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-918 | The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. |
| CWE-441 | The product receives a request, message, or directive from an upstream component, but the product does not sufficiently preserve the original source of the request before forwarding the request to an external actor that is outside of the product's control sphere. This causes the product to appear to be the source of the request, leading it to act as a proxy or other intermediary between the upstream component and the external actor. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability affects Skipper, an HTTP router and reverse proxy used for service composition. Before version 0.24.0, when Skipper was used as an Ingress controller, users who had permissions to create an Ingress and a Service of type ExternalName could create routes that allowed them to use Skipper's network access to reach internal services. This could potentially expose internal services to unauthorized access. Version 0.24.0 addresses this by disabling Kubernetes ExternalName by default, and developers can use allow lists for ExternalName targets as a workaround.
How can this vulnerability impact me? :
This vulnerability can allow users with certain permissions to create routes that use Skipper's network access to reach internal services that might otherwise be inaccessible. This could lead to unauthorized access to internal network resources, potentially exposing sensitive data or internal systems to attackers or unauthorized users.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, upgrade Skipper to version 0.24.0 or later, which disables Kubernetes ExternalName by default. Alternatively, configure Skipper to allow list targets of an ExternalName and allow list via regular expressions to control access.