CVE-2026-106503
highpriority · track · 0EPSS 0.004 · 31 %ileUSEPSS · scored 2026-10-24
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (11)
Products and version ranges known to be affected.
- linuxfoundation backstage/plugin-scaffolder-backend< 3.3.1nvdUScpe:2.3:a:linuxfoundation:backstage\/plugin-scaffolder-backend:*:*:*:*:*:*:*:*
- linuxfoundation backstage/plugin-scaffolder-backend3.4.0 → 3.4.1nvdUScpe:2.3:a:linuxfoundation:backstage\/plugin-scaffolder-backend:*:*:*:*:*:*:*:*
- linuxfoundation backstage/plugin-scaffolder-backend4.0.0 → 4.0.3nvdUScpe:2.3:a:linuxfoundation:backstage\/plugin-scaffolder-backend:*:*:*:*:*:*:*:*
- linuxfoundation backstage/plugin-scaffolder-backend4.0.4 → 4.1.0nvdUScpe:2.3:a:linuxfoundation:backstage\/plugin-scaffolder-backend:*:*:*:*:*:*:*:*
- npm @backstage/plugin-scaffolder-backend3.4.0 → 3.4.1osvUSpkg:npm/%40backstage/plugin-scaffolder-backend
- npm @backstage/plugin-scaffolder-backend4.0.0 → 4.0.3osvUSpkg:npm/%40backstage/plugin-scaffolder-backend
- npm @backstage/plugin-scaffolder-backend4.0.4 → 4.1.0osvUSpkg:npm/%40backstage/plugin-scaffolder-backend
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-hmp2-4m7g-22cvBackstage: Scaffolder action input authorization bypass2026-10-07ghsa · osvUS
### Impact 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. ### Patches Patched in `@backstage/plugin-scaffolder-backend` version `4.1.0` ### Workarounds - Restrict affected Scaffolder actions to trusted users and configure source-control integrations with least-privilege credentials.
sources
Which sources assert this record, and when.
references (7) nvd
External citations — patches, advisories, analysis.
- https://github.com/backstage/backstage/commit/11c1384c0649b8ab26391c6a4e4f34b80ab0d188Patch
- https://github.com/backstage/backstage/commit/a91ed72d540e80b62a73b39bb1563ff5018d52d1Patch
- https://github.com/backstage/backstage/commit/e307e4f487103d815e484291b3fda778ab9983bfPatch
- https://github.com/backstage/backstage/releases/tag/v1.49.6PatchRelease Notes
- https://github.com/backstage/backstage/releases/tag/v1.50.5PatchRelease Notes
- https://github.com/backstage/backstage/releases/tag/v1.54.6PatchRelease Notes
- https://github.com/backstage/backstage/security/advisories/GHSA-hmp2-4m7g-22cvMitigationVendor Advisory
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