---
id: CVE-2026-106563
title: Backstage is an open framework for building developer portals
summary: >-
  Backstage is an open framework for building developer portals. Prior to
  0.21.8, the @backstage/plugin-kubernetes-backend package is affected by
  improper entity validation in deprecated kubernetes services endpoint. An
  authenticated user …
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-20
  - CWE-862
vendor: backstage
product: backstage
affected:
  - backstage < 1.54.1
  - plugin-kubernetes-backend < 0.21.8
published: '2026-10-07'
updated: '2026-10-07'
sourceUpdated: '2026-10-07T15:52:18.453'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-106563'
references:
  - url: >-
      https://github.com/backstage/backstage/commit/2d5d3e77d630455d6d48cfa8f31fd3c126fd6f29
    label: security-advisories@github.com
  - url: 'https://github.com/backstage/backstage/releases/tag/v1.54.1'
    label: security-advisories@github.com
  - url: >-
      https://github.com/backstage/backstage/security/advisories/GHSA-r9ph-3637-55px
    label: security-advisories@github.com
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-106563'
  - url: 'https://github.com/advisories/GHSA-r9ph-3637-55px'
tags:
  - nvd
  - cve.org
  - ghsa
  - npm
ingestedAt: '2026-10-07T15:36:04.054Z'
aliases:
  - GHSA-r9ph-3637-55px
ecosystem: npm
patched:
  - '@backstage/plugin-kubernetes-backend 0.21.8'
---

## Overview

Backstage is an open framework for building developer portals. Prior to 0.21.8, the @backstage/plugin-kubernetes-backend package is affected by improper entity validation in deprecated kubernetes services endpoint. An authenticated user with Kubernetes read permissions could access Kubernetes workload data beyond their intended scope by supplying crafted entity data to the deprecated services endpoint. The exposure is limited to read-only access to Kubernetes object metadata across configured clusters. This issue is fixed in version 0.21.8.

## Remediation

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

## Package advisory (CVE-2026-106563)

Affected packages:

- `@backstage/plugin-kubernetes-backend < 0.21.8`

Patched in:

- `@backstage/plugin-kubernetes-backend 0.21.8`

Source: https://github.com/advisories/GHSA-r9ph-3637-55px