Backstage: Unsupported catalog cluster authentication mode in kubernetes backend
Impact
Deployments using catalog cluster discovery may be affected when catalog contributors can create or modify kubernetes-cluster Resource entities. With the required endpoint permissions and pod RBAC, the backend can use its local in-cluster identity, potentially exposing Kubernetes resources readable by that identity. The credential is used only with the local in-cluster API endpoint and is not sent to the catalog-supplied endpoint.
Patches
Patched in @backstage/plugin-kubernetes-backend version 0.21.10
Workarounds
- Do not configure service account authentication through catalog-provided clusters; use the supported static configuration method when service account authentication is required.
- Restrict catalog ingestion so untrusted users cannot create or alter Kubernetes cluster Resource entities.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | @backstage/plugin-kubernetes-backend | < 0.21.10 | 0.21.10 |
References
- https://github.com/backstage/backstage/security/advisories/GHSA-h53x-hjx6-25gr
- https://nvd.nist.gov/vuln/detail/CVE-2026-106487
- https://github.com/backstage/backstage/commit/c14f8be6908f0f719b16356e5492352311e28946
- https://github.com/backstage/backstage
- https://github.com/backstage/backstage/releases/tag/v1.54.6
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N- Weakness (CWE)
CWE-441- Platform
- npm
- Package
@backstage/plugin-kubernetes-backend- Disclosed
- 07.10.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-h53x-hjx6-25gr - CC BY 4.0
Vulnerability history: @backstage/plugin-kubernetes-backend
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 3
- First → latest
- 10.2026 10.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Medium 2
- Low 1
Disclosures per year
- 2026: 3
-
Backstage: Unsupported catalog cluster authentication mode in kubernetes backend this entry
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