CVE-2026-106487 Backstage: Unsupported catalog cluster authentication mode in kubernetes backend
Attackers with catalog permissions can bypass authentication modes to access Kubernetes resources via the backend's local identity.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-106487?
CVE-2026-106487 is a low-severity vulnerability in Linuxfoundation Backstage, published on 6 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Backstage is an open framework for building developer portals. Prior to 0.21.10, the @backstage/plugin-kubernetes-backend package is affected by unsupported catalog cluster authentication mode in kubernetes backend. 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. This issue is fixed in version 0.21.10.
Weakness: CWE-441
Which versions are affected by CVE-2026-106487?
2 open source packages ship an affected version, including @backstage/plugin-kubernetes-backend. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
@backstage/plugin-kubernetes-backend npm | All versions | 0.21.10 |
@backstage/plugin-kubernetes-backend npm | All versions | 0.21.10 |
Products include Linuxfoundation Backstage, Linuxfoundation Backstage\/Plugin-Kubernetes-Backend.
How do I fix CVE-2026-106487?
Upgrade @backstage/plugin-kubernetes-backend to 0.21.10 or later.
Is CVE-2026-106487 being exploited?
There is no known exploitation of CVE-2026-106487 in the wild and no public exploit code.
Other vulnerabilities in Linuxfoundation Backstage
- CVE-2026-106501 Backstage: Sensitive information exposure in Scaffolder
- CVE-2026-106558 Backstage: Improper validation of TechDocs MkDocs configuration
- CVE-2026-88064 Backstage: Improper input validation in TechDocs MkDocs configuration
- CVE-2026-106459 Backstage: Improper input validation in Sentry scaffolder actions
- CVE-2026-106486 Backstage: Improper filesystem validation in Bitbucket pull-request scaffolder actions
Sources
Also known as GHSA-h53x-hjx6-25gr.