CVE-2026-24470: Github.com/zalando/skipper Skipper Ingress Controller Allows Unauthorized Vulnerability
HIGHCVE-2026-24470 is a HIGH (CVSS 8.1) skipper ingress controller allows unauthorized vulnerability (CWE-441: Unintended Proxy or Intermediary ('Confused Deputy')) affecting Github.com/zalando/skipper libraries in the Go ecosystem. The issue involves skipper ingress controller allows unauthorized access to internal services via externalname. Remediation is available by upgrading affected packages to version 0.24.0.
CVE-2026-24470 at a Glance
Security Impact
CVSS: 8.1
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N).
How to Fix CVE-2026-24470
To remediate this vulnerability, upgrade all affected Github.com/zalando/skipper dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/zalando/skipper to 0.24.0Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/zalando/skipperHow to Check if You Are Affected
To determine whether your application is affected by CVE-2026-24470, inspect your project dependencies for Github.com/zalando/skipper:
inspect dependencies for github.com/zalando/skipperAnalyze the terminal output to locate any version of Github.com/zalando/skipper in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.24.0), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-441: Unintended Proxy or Intermediary ('Confused Deputy'), where 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. In Github.com/zalando/skipper, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-24470 Affected Github.com/zalando/skipper Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/zalando/skipper
|
Go |
< 0.24.0
|
0.24.0
|
References
Frequently Asked Questions
What is CVE-2026-24470?
Which Github.com/zalando/skipper versions are affected?
What version fixes CVE-2026-24470?
Is github.com/zalando/skipper affected?
What is the CVSS score of CVE-2026-24470?
What CWE is associated with CVE-2026-24470?
How can I check Go dependencies for CVE-2026-24470?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-mxxc-p822-2hx9",
"modified" : "2026-01-29T03:24:42Z",
"published" : "2026-01-26T23:26:56Z",
"aliases" : [ "CVE-2026-24470" ],
"summary" : "Skipper Ingress Controller Allows Unauthorized Access to Internal Services via ExternalName",
"details" : "### Impact\n\nWhen 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.\n\n### Patches\n\nhttps://github.com/zalando/skipper/releases/tag/v0.24.0 disables Kubernetes ExternalName by default.\n\n### Workarounds\n\nDevelopers can allow list targets of an ExternalName by using `-kubernetes-only-allowed-external-names=true` and allow list via regular expressions `-kubernetes-allowed-external-name '^[a-z][a-z0-9-.]+[.].allowed.example$'` \n\n### References\n\nhttps://kubernetes.io/docs/concepts/services-networking/service/#externalname",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/zalando/skipper"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "0.24.0"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/zalando/skipper/security/advisories/GHSA-mxxc-p822-2hx9"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-24470"
}, {
"type" : "WEB",
"url" : "https://github.com/zalando/skipper/commit/a4c87ce029a58eb8e1c2c1f93049194a39cf6219"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/zalando/skipper"
}, {
"type" : "WEB",
"url" : "https://github.com/zalando/skipper/releases/tag/v0.24.0"
}, {
"type" : "WEB",
"url" : "https://kubernetes.io/docs/concepts/services-networking/service/#externalname"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-441", "CWE-918" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2026-01-26T23:26:56Z",
"nvd_published_at" : "2026-01-26T23:16:09Z"
}
}