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OpenAdvisories
Medium · 4.3 CVE-2026-54247 EUVD-2026-78062GHSA-cwxq-rc9x-2jvvGO-2026-6015

Skipper: Unbounded Request Body Read in Admission Webhook Causes Memory Exhaustion DoS

Published Sep 14, 2026 · Updated Sep 16, 2026 · Assigned by GitHub_M

Description

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.

Affected products

VendorProductAffectedFixed
zalando skipper < 0.26.22 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/zalando/skipper < 0.26.22 0.26.22 GHSA-cwxq-rc9x-2jvv

Advisories 1

References