CVE-2026-106503
Backstage: Scaffolder action input authorization bypass
HIGH 8.1
At a glance
- Source
- NVD
- EPSS
- EPSS 0.49 % · percentile 42 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
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.
Weaknesses (CWE)
References
- https://github.com/backstage/backstage/security/advisories/GHSA-hmp2-4m7g-22cv
- https://github.com/backstage/backstage/commit/11c1384c0649b8ab26391c6a4e4f34b80ab0d188
- https://github.com/backstage/backstage/commit/a91ed72d540e80b62a73b39bb1563ff5018d52d1
- https://github.com/backstage/backstage/commit/e307e4f487103d815e484291b3fda778ab9983bf
- https://github.com/backstage/backstage/releases/tag/v1.49.6
- https://github.com/backstage/backstage/releases/tag/v1.50.5
- https://github.com/backstage/backstage/releases/tag/v1.54.6
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N | GitHub_M |
| CVSS 3.1 | HIGH 8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-hmp2-4m7g-22cv — Backstage: Scaffolder action input authorization bypass
European references
- ENISA EUVD · EUVD-2026-94068
- GCVE · GCVE-0-2026-106503
Affected configurations (NVD CPE)
cpe:2.3:a:linuxfoundation:backstage\/plugin-scaffolder-backend:*:*:*:*:*:*:*:*< 3.3.1cpe:2.3:a:linuxfoundation:backstage\/plugin-scaffolder-backend:*:*:*:*:*:*:*:*≥ 3.4.0 < 3.4.1cpe:2.3:a:linuxfoundation:backstage\/plugin-scaffolder-backend:*:*:*:*:*:*:*:*≥ 4.0.0 < 4.0.3cpe:2.3:a:linuxfoundation:backstage\/plugin-scaffolder-backend:*:*:*:*:*:*:*:*≥ 4.0.4 < 4.1.0cpe:2.3:a:linuxfoundation:backstage:*:*:*:*:*:*:*:*< 1.49.6cpe:2.3:a:linuxfoundation:backstage:*:*:*:*:*:*:*:*≥ 1.50.0 < 1.50.5cpe:2.3:a:linuxfoundation:backstage:*:*:*:*:*:*:*:*≥ 1.51.0 < 1.54.6
Affected products
| Product | Versions |
|---|---|
| backstage · backstage | affected < 1.49.6 ; affected >= 1.50.0-next.0, < 1.50.5 ; affected >= 1.51.0-next.0, < 1.54.6 |
| @backstage · plugin-scaffolder-backend | affected < 3.3.1 ; affected >= 3.4.0, < 3.4.1 ; affected >= 4.0.0, < 4.0.3 ; affected >= 4.0.4, < 4.1.0 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |