CVE-2023-35926
HighCVSS 8.0Exploitation Probability (EPSS)
Elevated risk71th percentile - higher than 71% of all known CVEs
Summary
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.
Risk Assessment
The organization may be exposed to remote code execution, potentially leading to the compromise of the scaffolder-backend instance. This poses a serious threat to data and system security.
Recommendation
It is recommended to update the `@backstage/plugin-scaffolder-backend` plugin to version 1.15.0 to mitigate this vulnerability. Additionally, access to registered templates should be reviewed to minimize risk.
Other vulnerabilities in @backstage/plugin-scaffolder-backend
See all- CVE-2026-106506Medium
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.
- 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.
Original NVD description (English source)
Backstage is an open platform for building developer portals. The Backstage scaffolder-backend plugin uses a templating library that requires sandbox, as it by design allows for code injection. The library used for this sandbox so far has been `vm2`, but in light of several past vulnerabilities and existing vulnerabilities that may not have a fix, the plugin has switched to using a different sandbox library. A malicious actor with write access to a registered scaffolder template could manipulate the template in a way that allows for remote code execution on the scaffolder-backend instance. This was only exploitable in the template YAML definition itself and not by user input data. This is vulnerability is fixed in version 1.15.0 of `@backstage/plugin-scaffolder-backend`.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

