CVE-2026-106561 Backstage: Sensitive information disclosure in Kubernetes resource queries
Authenticated users can retrieve sensitive Kubernetes resource data that should be masked, exposing credentials and confidential material in connected clusters.
- 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-2026-106561?
CVE-2026-106561 is a medium-severity vulnerability in Linuxfoundation Backstage, published on 7 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 0.21.9, 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.
Which versions are affected by CVE-2026-106561?
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 | 0.21.9 |
@backstage/plugin-kubernetes-backend npm | All versions | 0.21.9 |
Products include Linuxfoundation Backstage, Linuxfoundation Backstage\/Plugin-Kubernetes-Backend.
How do I fix CVE-2026-106561?
Upgrade @backstage/plugin-kubernetes-backend to 0.21.9 or later.
Is CVE-2026-106561 being exploited?
There is no known exploitation of CVE-2026-106561 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-p795-mqf2-36mf.