Backstage: Improper task state validation in Scaffolder backend

### Impact An authenticated user with permission to create and access Scaffolder tasks may, under specific timing and deployment conditions, affect files accessible to the Backstage backend. If backend application files are writable, the confidentiality, integrity, and availability of the backend may be compromised. ### Patches Patched in `@backstage/plugin-scaffolder-backend` version `4.1.0` ### Workarounds - Restrict Scaffolder task creation and task-read permissions to trusted users through the permission policy. - Limit who can register or modify templates and which Scaffolder actions may execute. - Run backend application files read-only outside a dedicated, least-privilege Scaffolder working directory. ### References - [Authorizing Scaffolder tasks, parameters, steps, and actions](https://backstage.io/docs/features/software-templates/authorizing-scaffolder-template-details/)

Source published

7 Oct 2026 17:59:02 UTC

Source modified

7 Oct 2026 18:15:10 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Publisher rating · HIGH