CVE-2026-106503 PUBLISHED

Backstage: Scaffolder action input authorization bypass

Assigner: GitHub_M
Reserved: 06.10.2026 Published: 06.10.2026 Updated: 06.10.2026

Backstage is an open framework for building developer portals. 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. Depending on integration credentials, this could grant unauthorized access to repositories and related source-control resources. This issue is fixed in versions 3.3.1, 3.4.1, 4.0.3 and 4.1.0.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
CVSS Score: 8.1

Product Status

Vendor backstage
Product backstage
Versions
  • Version < 1.49.6 is affected
  • Version >= 1.50.0-next.0, < 1.50.5 is affected
  • Version >= 1.51.0-next.0, < 1.54.6 is affected
Vendor @backstage
Product plugin-scaffolder-backend
Versions
  • Version < 3.3.1 is affected
  • Version >= 3.4.0, < 3.4.1 is affected
  • Version >= 4.0.0, < 4.0.3 is affected
  • Version >= 4.0.4, < 4.1.0 is affected

References

Problem Types

  • CWE-178: Improper Handling of Case Sensitivity CWE
  • CWE-284: Improper Access Control CWE