CVE-2026-106462 in Backstage
Summary
by MITRE • 10/07/2026
Backstage is an open framework for building developer portals. Prior to 1.54.6, scaffolder source-control actions may not consistently enforce intended credential boundaries. An authenticated user could cause an affected action to fall back to broader integration credentials and perform operations with more access than intended. This issue is fixed in 1.54.6 when operators also enable scaffolder.requireScmUserCredentials after upgrading.
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Analysis
by VulDB Data Team • 10/07/2026
Backstage serves as a comprehensive open framework designed for the creation of internal developer portals, streamlining software development lifecycles by integrating various tools and services into a unified interface. Within this ecosystem, the scaffolder component plays a critical role in automating project setup and infrastructure provisioning through configurable actions that interact with external systems such as version control platforms like GitHub or GitLab. These interactions typically require authentication credentials to perform operations including repository creation, branch management, and code commits. The security model relies heavily on strict credential boundaries to ensure that automated processes operate within the least privilege principle, preventing unauthorized access or excessive permissions from being applied during these automated workflows.
A significant vulnerability existed in versions of Backstage prior to 1.54.6 regarding how scaffolder source-control actions handled authentication credentials. Specifically, there was an inconsistency in enforcing intended credential boundaries when executing certain operations against version control systems. In this flawed state, if a specific user-defined or action-specific credential configuration failed validation or was unavailable for any reason, the system would not fail securely as expected. Instead, it exhibited a fallback behavior that defaulted to broader integration credentials configured at the platform level. This means an authenticated user could trigger actions where the intended restrictive permissions were bypassed, allowing the operation to proceed using higher-privilege administrative tokens associated with the Backstage instance itself rather than the scoped token meant for that specific task or user context.
The operational impact of this vulnerability is substantial because it effectively allows privilege escalation within the scope of version control operations. An attacker who has authenticated access to the developer portal could manipulate scaffolder actions to perform repository management tasks, such as creating new repositories, pushing code changes, or modifying settings with elevated privileges that were not intended for their role. This undermines the principle of least privilege and poses a risk of unauthorized modifications to source code repositories, potential data exfiltration if sensitive information is committed, or disruption of development workflows through destructive actions performed under an administrative identity. The severity is compounded by the fact that this behavior occurs during standard operational activities, making it difficult for operators to distinguish between legitimate high-privilege operations and malicious exploitation without deep log analysis.
To mitigate this vulnerability, organizations running Backstage must upgrade their instances to version 1.54.6 or later. However, upgrading alone is insufficient due to backward compatibility concerns; the fix requires a deliberate configuration change by system operators. Specifically, administrators must enable the scaffolder.requireScmUserCredentials setting in the backend configuration file. This parameter enforces strict validation that ensures every source-control action utilizes explicitly defined user credentials rather than falling back to broader integration tokens. By enforcing this requirement, Backstage guarantees that actions fail if specific credentials are not provided or valid, thereby maintaining tight control over permission boundaries and preventing the unintended elevation of privileges described in the vulnerability report. This configuration change aligns with industry best practices for secure credential management as outlined in CWE-250 regarding execution with unnecessary privileges and supports adherence to ATT&CK techniques related to privilege escalation within cloud environments.