Skipper is an HTTP router and reverse proxy for service composition. Prior to 0.27.13, the routesrv component serves cluster-wide control-plane data without application-layer authentication through /routes, /routes/{zone}, /swarm/redis/shards, and /swarm/valkey/shards. The handlers registered in routesrv/routesrv.go, eskipBytes.ServeHTTP in routesrv/eskipbytes.go, RedisHandler.ServeHTTP in routesrv/redishandler.go, and ValkeyHandler.ServeHTTP in routesrv/valkeyhandler.go only restrict HTTP methods and do not authenticate callers. A compromised or otherwise attacker-controlled pod that can reach routesrv on the Kubernetes cluster network can bypass its namespace-scoped RBAC and read Ingress and RouteGroup backend URLs, filter-chain and OAuth or OIDC path details, and Redis or Valkey shard addresses across namespaces. NetworkPolicy can restrict reachability but does not remove the missing-authentication condition, and the established impact is confidentiality exposure rather than direct integrity or availability loss. This issue is fixed in version 0.27.13.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-5587-2x54-jj6h Skipper's routesrv-no-auth component: All routesrv API Endpoints Lack Authentication
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 15 Sep 2026 05:00:00 +0000

Type Values Removed Values Added
First Time appeared Zalando
Zalando skipper
Vendors & Products Zalando
Zalando skipper

Mon, 14 Sep 2026 21:00:00 +0000

Type Values Removed Values Added
Description Skipper is an HTTP router and reverse proxy for service composition. Prior to 0.27.13, the routesrv component serves cluster-wide control-plane data without application-layer authentication through /routes, /routes/{zone}, /swarm/redis/shards, and /swarm/valkey/shards. The handlers registered in routesrv/routesrv.go, eskipBytes.ServeHTTP in routesrv/eskipbytes.go, RedisHandler.ServeHTTP in routesrv/redishandler.go, and ValkeyHandler.ServeHTTP in routesrv/valkeyhandler.go only restrict HTTP methods and do not authenticate callers. A compromised or otherwise attacker-controlled pod that can reach routesrv on the Kubernetes cluster network can bypass its namespace-scoped RBAC and read Ingress and RouteGroup backend URLs, filter-chain and OAuth or OIDC path details, and Redis or Valkey shard addresses across namespaces. NetworkPolicy can restrict reachability but does not remove the missing-authentication condition, and the established impact is confidentiality exposure rather than direct integrity or availability loss. This issue is fixed in version 0.27.13.
Title Skipper routesrv-no-auth: All routesrv API Endpoints Lack Authentication
Weaknesses CWE-306
References
Metrics cvssV3_1

{'score': 5.7, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-14T20:03:14.613Z

Reserved: 2026-06-12T16:25:43.085Z

Link: CVE-2026-54246

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-14T20:16:45.697

Modified: 2026-09-14T20:16:45.697

Link: CVE-2026-54246

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-15T04:45:11Z

Weaknesses