CVE-2026-24470

EUVD-2026-4831

26.01.2026, 23:16

Skipper is an HTTP router and reverse proxy for service composition. Prior to version 0.24.0, when running Skipper as an Ingress controller, users with permissions to create an Ingress and a Service of type ExternalName can create routes that enable them to use Skipper's network access to reach internal services. Version 0.24.0 disables Kubernetes ExternalName by default. As a workaround, developers can allow list targets of an ExternalName and allow list via regular expressions.

Confused Deputy

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	8.1 HIGH	NETWORK	LOW	LOW	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
GitHub_M	CNA	8.1 HIGH	NETWORK	LOW	LOW	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Base Score

CVSS 3.x

EPSS Score

Percentile: 7%

Affected Products (NVD)

Vendor	Product	Version
zalando	skipper	𝑥 < 0.24.0

𝑥

= Vulnerable software versions

Common Weakness Enumeration

CWE-441 - Unintended Proxy or Intermediary ('Confused Deputy')
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.

References

https://github.com/zalando/skipper/commit/a4c87ce029a58eb8e1c2c1f93049194a39cf6219

https://github.com/zalando/skipper/security/advisories/GHSA-mxxc-p822-2hx9

https://kubernetes.io/docs/concepts/services-networking/service/#externalname