CVE-2026-106500
highpriority · track · 0EPSS 0.003 · 27 %ileUSEPSS · scored 2026-10-27
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 improper task state validation in scaffolder backend. 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. 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
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (8)
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:*:*:*:*:*:*:*:*
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-xvgh-hmx8-9xxfBackstage: Improper task state validation in Scaffolder backend2026-10-07ghsa · osvUS
### 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/)
sources
Which sources assert this record, and when.
references (7) nvd
External citations — patches, advisories, analysis.
- https://github.com/backstage/backstage/commit/0d24f1b8701f3dde6cd597f81997c1ea873a43aePatch
- https://github.com/backstage/backstage/commit/56be299dd3ef6706e13e76ea2f8a9b0dd0b6413dPatch
- https://github.com/backstage/backstage/commit/9e86c95a1a3ddfd54db03731cd8678aa63495175Patch
- 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-xvgh-hmx8-9xxfMitigationVendor Advisory
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