Disclosure summary
### 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-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
GitHub Reviewed Security Advisories · GHSA-xvgh-hmx8-9xxf
Open original source · Updated Oct 07, 2026
Backstage: Improper task state validation in Scaffolder backend
Source severity: HIGH / 0
| Ecosystem | Package | Affected range | First patched |
|---|---|---|---|
| npm | @backstage/plugin-scaffolder-backend | < 4.1.0 | 4.1.0 |
Original records & references
- NIST NVD record
- CVE Program record
- github.com — Reviewed advisory
PUBLISHED 2026-10-07T13:59:02-04:00
MODIFIED 2026-10-07T13:59:03-04:00
INGESTED 2026-10-08T12:05:11-04:00