Medium · CVSS 5.0CVE-2026-106561

Backstage: Sensitive information disclosure in Kubernetes resource queriesCVE-2026-106561

Answer in brief

CVE-2026-106561 records a Medium severity (CVSS 5.0) vulnerability in Backstage: Sensitive information disclosure in Kubernetes resource queries. The current sources do not mark it as known exploited. The current feed maps backstage/backstage (generic), @backstage/plugin-kubernetes-backend (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

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

Published Oct 7, 2026Updated Oct 7, 2026Source checked Oct 7, 2026First seen by HOL Oct 7, 2026Material review Oct 7, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.0
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 5.0. 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 backstage/backstage (generic), @backstage/plugin-kubernetes-backend (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
backstage/backstagegeneric	<1.54.2	1.54.2
@backstage/plugin-kubernetes-backendgeneric	<0.21.9	0.21.9

Recommended response

Check inventory. Check lockfiles and deployed manifests for backstage/backstage, @backstage/plugin-kubernetes-backend.
Review the reported fix. Update backstage/backstage to 1.54.2; @backstage/plugin-kubernetes-backend to 0.21.9 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 7, 2026

Sources and claim methodology

Upstream source description

Backstage is an open framework for building developer portals. Prior to 0.21.9, the @backstage/plugin-kubernetes-backend package is affected by sensitive information disclosure in kubernetes resource queries. An authenticated user holding the standard Kubernetes resource read permission could retrieve sensitive values that the Kubernetes plugin is designed to mask, potentially exposing credentials and other confidential material held in the connected clusters. Exposure is limited to resources that the Backstage service account is permitted to read and that match the targeted catalog entity's namespace and label selector. Deployments whose cluster credentials do not grant read access to these resources are unaffected. This issue is fixed in version 0.21.9.

Quoted source text, attributed separately from HOL analysis.