CVE-2026-106506
MediumCVSS 5.3Summary
Backstage is an open framework for building developer portals. Prior to 4.1.0, the @backstage/plugin-scaffolder-backend package is affected by improper input validation in scaffolder task list ordering. An authenticated Backstage user with permission to create and read relevant scaffolder tasks may be able to infer confidential task data under specific conditions. Successful exploitation requires retained task secrets, visibility of a target task, knowledge of the secret structure, and repeated requests. Fixed in version 4.1.0.
Risk Assessment
The risk is the potential disclosure of confidential scaffolder task data, which may lead to confidentiality breaches of information processed by Backstage.
Recommendation
Update the @backstage/plugin-scaffolder-backend package to version 4.1.0 or later, and restrict user permissions for creating and reading tasks.
Other vulnerabilities in @backstage/plugin-scaffolder-backend
See all- CVE-2026-106504Medium
Backstage is an open framework for building developer portals. Prior to 4.1.0, the @backstage/plugin-scaffolder-backend package is affected by sensitive information exposure in scaffolder task logs. An authenticated user who can create and read scaffolder tasks may be able to observe sensitive values in task logs in deployments with restrictive action permissions and affected templates. Exploitation requires a denied action whose input contains such a value. Fixed in version 4.1.0.
- CVE-2026-106503High
In Backstage prior to 3.3.1, 3.4.1, 4.0.3 and 4.1.0, the @backstage/plugin-scaffolder-backend package is affected by scaffolder action input authorization bypass. An authenticated user with access to affected Scaffolder templates could bypass configured action restrictions, potentially granting unauthorized access to repositories and related source-control resources.
- CVE-2026-106502Medium
Backstage is an open framework for building developer portals. Prior to 4.1.0, the @backstage/plugin-scaffolder-backend package could expose sensitive information in Scaffolder task failure events. Under specific template and failure conditions, an authenticated user may retrieve backend-managed credentials used during task execution from affected task events. Fixed in version 4.1.0.
- CVE-2026-106500High
In Backstage prior to 3.3.1, 3.4.1, 4.0.3 and 4.1.0, the @backstage/plugin-scaffolder-backend package is affected by improper task state validation. An authenticated user with permission to create and access Scaffolder tasks may, under specific conditions, affect files accessible to the Backstage backend, potentially compromising confidentiality, integrity, and availability.
- CVE-2026-106461Medium
In @backstage/plugin-scaffolder-backend prior to 4.1.0, incorrect authorization in scaffolder task listing allows an authenticated internal user to view metadata for tasks outside the intended visibility. Stored task secrets are not included, and no integrity or availability impact was identified. Fixed in version 4.1.0.
- CVE-2023-35926High
A vulnerability in the scaffolder-backend plugin of the Backstage platform allows for remote code execution by a malicious actor with access to a registered template. The issue arises from the use of a templating library that requires a sandbox, which permits code injection.
Original NVD description (English source)
Backstage is an open framework for building developer portals. Prior to 4.1.0, the @backstage/plugin-scaffolder-backend package is affected by improper input validation in scaffolder task list ordering. An authenticated Backstage user with permission to create and read relevant scaffolder tasks may be able to infer confidential task data under specific conditions. Successful exploitation requires retained task secrets, visibility of a target task, knowledge of the secret structure, and repeated requests. This issue is fixed in version 4.1.0.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS