CVE-2026-106497 in Backstage
Summary
by MITRE • 10/07/2026
Backstage is an open framework for building developer portals. Prior to 3.9.1, the @backstage/plugin-catalog-backend package is affected by inconsistent catalog property permission evaluation. In deployments that use affected value-based catalog permission conditions as a confidentiality boundary, an authenticated user could receive catalog entity data that policy authors intended to restrict. This issue is fixed in version 3.9.1.
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified within the Backstage developer portal framework specifically impacts the @backstage/plugin-catalog-backend package prior to version 3.9.1. Backstage serves as a central platform for organizing and managing software infrastructure, making its catalog component critical for maintaining accurate inventories of microservices, libraries, and other digital assets. The core issue lies in an inconsistent evaluation mechanism regarding property-based permissions within the catalog backend. This flaw allows authenticated users to bypass intended confidentiality boundaries established by policy authors who rely on value-based conditions to restrict access to specific entity data.
From a technical perspective, the vulnerability stems from how the permission system processes and evaluates attributes associated with catalog entities. When administrators configure policies that use property values as criteria for granting or denying access, the backend fails to consistently apply these rules across all request contexts. This inconsistency creates a logic flaw where certain authenticated requests are processed without strictly adhering to the defined restrictive conditions. Consequently, users who should be denied access based on their role or group membership may successfully retrieve sensitive metadata, configuration details, or internal documentation associated with restricted entities.
The operational impact of this vulnerability is significant for organizations treating Backstage as a primary confidentiality boundary for developer resources. Unauthorized disclosure of catalog entity data can lead to information leakage regarding internal architecture, proprietary code dependencies, and infrastructure configurations. Attackers leveraging authenticated accounts could map out the organization's software landscape more accurately than intended, potentially identifying high-value targets or weak points in the deployment pipeline. This aligns with CWE-284 Improper Access Control, as the system fails to enforce appropriate restrictions on authorized functionality, allowing users to access resources beyond their designated privileges.
Furthermore, this vulnerability facilitates reconnaissance activities that are characteristic of early-stage attacks described in the MITRE ATT&CK framework under techniques such as T1087 Account Discovery and T1526 Service Scan. By exposing internal entity details, the flaw aids adversaries in understanding the environment's structure without needing to exploit additional vulnerabilities for initial access or privilege escalation. The risk is compounded by the fact that Backstage often integrates with other critical DevOps tools, meaning leaked catalog data could inform further exploitation attempts against connected systems like CI/CD pipelines or container registries.
To mitigate this vulnerability, organizations running affected versions of Backstage must immediately upgrade to version 3.9.1 or later where the permission evaluation logic has been corrected. It is also advisable for administrators to review existing catalog policies and ensure that critical data does not rely solely on property-based permissions without additional layers of security such as network-level access controls or robust identity provider integration. Regular audits of permission configurations can help identify any residual inconsistencies, ensuring that confidentiality boundaries remain effective against both internal misconfigurations and external threats seeking to exploit authentication bypasses.