---
id: CVE-2026-54247
title: Skipper is an HTTP router and reverse proxy for service composition
summary: >-
  Skipper is an HTTP router and reverse proxy for service composition. Prior to
  0.26.22, Handler in dataclients/kubernetes/admission/admission.go passes the
  body of requests to the Kubernetes admission endpoint at :9443/admission
  directly …
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-770
vendor: zalando
product: skipper
affected:
  - skipper < 0.26.22
patched:
  - github.com/zalando/skipper 0.26.22
published: '2026-09-14'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T17:17:20.600'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-54247'
references:
  - url: >-
      https://github.com/zalando/skipper/commit/c3d156c6caaefecc9a46774c0f9c3c70b97160b4
    label: security-advisories@github.com
  - url: 'https://github.com/zalando/skipper/pull/4053'
    label: security-advisories@github.com
  - url: 'https://github.com/zalando/skipper/releases/tag/v0.26.22'
    label: security-advisories@github.com
  - url: 'https://github.com/zalando/skipper/security/advisories/GHSA-cwxq-rc9x-2jvv'
    label: security-advisories@github.com
  - url: 'https://github.com/advisories/GHSA-cwxq-rc9x-2jvv'
tags:
  - nvd
  - cve.org
  - ghsa
  - go
epss: 0.00298
epssPercentile: 0.20166
aliases:
  - GHSA-cwxq-rc9x-2jvv
ecosystem: go
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-16T16:19:01.486253Z'
ingestedAt: '2026-07-17T19:14:48.496Z'
---

## Overview

Skipper is an HTTP router and reverse proxy for service composition. Prior to 0.26.22, Handler in dataclients/kubernetes/admission/admission.go passes the body of requests to the Kubernetes admission endpoint at :9443/admission directly to io.ReadAll(r.Body) without a size limit. An attacker with in-cluster network access and a valid Kubernetes client certificate can send a very large body that causes unbounded memory allocation and an out-of-memory termination of the Skipper process. The disruption is limited to Ingress and RouteGroup admission rather than pod creation or unrelated admission controllers, and Kubernetes normally restarts the process. This issue is fixed in version 0.26.22.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-54247)

Affected packages:

- `github.com/zalando/skipper < 0.26.22`

Patched in:

- `github.com/zalando/skipper 0.26.22`

Source: https://github.com/advisories/GHSA-cwxq-rc9x-2jvv