[ CVE-2026-106503 · Published 6 Oct 2026 ]
Backstage: Scaffolder action input authorization bypass
CVSS 8.1
EPSS <1%Fix available
[ Description ]Official description
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.
[ Fixes ]Fixes and patches
- @backstage/plugin-scaffolder-backend 3.3.1Fixed version · GitHub Advisories · npm package @backstage/plugin-scaffolder-backend: upgrade to 3.3.1 or later (affected < 3.3.1)
- @backstage/plugin-scaffolder-backend 3.4.1Fixed version · GitHub Advisories · npm package @backstage/plugin-scaffolder-backend: upgrade to 3.4.1 or later (affected >= 3.4.0, < 3.4.1)
- @backstage/plugin-scaffolder-backend 4.0.3Fixed version · GitHub Advisories · npm package @backstage/plugin-scaffolder-backend: upgrade to 4.0.3 or later (affected >= 4.0.0, < 4.0.3)
- @backstage/plugin-scaffolder-backend 4.1.0Fixed version · GitHub Advisories · npm package @backstage/plugin-scaffolder-backend: upgrade to 4.1.0 or later (affected >= 4.0.4, < 4.1.0)
- Patch on github.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD
- Patch on github.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD
- Patch on github.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD
- Patch on github.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD
[ Packages ]Affected open-source packages
- @backstage/plugin-scaffolder-backend npmAffected < 3.3.1 · fixed in 3.3.1 · GHSA-hmp2-4m7g-22cv
- @backstage/plugin-scaffolder-backend npmAffected >= 3.4.0, < 3.4.1 · fixed in 3.4.1 · GHSA-hmp2-4m7g-22cv
- @backstage/plugin-scaffolder-backend npmAffected >= 4.0.0, < 4.0.3 · fixed in 4.0.3 · GHSA-hmp2-4m7g-22cv
- @backstage/plugin-scaffolder-backend npmAffected >= 4.0.4, < 4.1.0 · fixed in 4.1.0 · GHSA-hmp2-4m7g-22cv
[ References ]References
- github.com/backstage/backstage/commit/11c1384c0649b8ab26391c6a4e4f34b80ab0d188Patch
- github.com/backstage/backstage/commit/a91ed72d540e80b62a73b39bb1563ff5018d52d1Patch
- github.com/backstage/backstage/commit/e307e4f487103d815e484291b3fda778ab9983bfPatch
- github.com/backstage/backstage/releases/tag/v1.49.6PatchRelease Notes
- github.com/backstage/backstage/releases/tag/v1.50.5PatchRelease Notes
- github.com/backstage/backstage/releases/tag/v1.54.6PatchRelease Notes
- github.com/backstage/backstage/security/advisories/GHSA-hmp2-4m7g-22cvMitigationVendor Advisory