CVE-2026-106561: backstage

Vulnerability summary

CVE-2026-106561 is a medium (CVSS 5.0) vulnerability in backstage. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 8.8% of scored vulnerabilities.

Timeline

1. 07-10-2026
   PublishedVulnerability first disclosed.
2. 07-10-2026
   Last modifiedVulnerability information updated.

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.

• CWE-200Exposure of Sensitive Information to an Unauthorized ActorThe product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
• CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.