Skipper routesrv-no-auth: All routesrv API Endpoints Lack Authentication (CVE-2026-54246) | HOL Guard CVE

Medium severityCVE-2026-54246GHSA-5587-2X54-JJ6H

Skipper routesrv-no-auth: All routesrv API Endpoints Lack Authentication

Answer in brief

CVE-2026-54246 records a Medium severity vulnerability in Skipper routesrv-no-auth: All routesrv API Endpoints Lack Authentication. The current sources do not mark it as known exploited. The current feed maps zalando/skipper (generic), github.com/zalando/skipper (go). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 14, 2026Updated Sep 14, 2026Source checked Sep 14, 2026First seen by HOL Jul 18, 2026Material review Sep 14, 2026

Upstream Advisory

Key facts

Risk: Medium
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps zalando/skipper (generic), github.com/zalando/skipper (go). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
zalando/skippergeneric	< 0.27.13	Not reported
github.com/zalando/skippergo	<0.27.13	0.27.13

Recommended response

Check inventory. Check lockfiles and deployed manifests for zalando/skipper, github.com/zalando/skipper.
Review the reported fix. Update github.com/zalando/skipper to 0.27.13 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jul 18, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.