CVE-2026-106500
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.34%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 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 3.1
- 8.5 HIGHCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 0.34% probability · 27th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-59, CWE-362
- Affected
- linuxfoundation/backstage\/plugin-scaffolder-backend · linuxfoundation/backstage
- Source
- security-advisories@github.com
EPSS moved from 0.3% on 7 October 2026 to 0.3% on 26 October 2026.
References
- 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/v1.49.6Patch, Release Notes
- https://github.com/backstage/backstage/releases/tag/v1.50.5Patch, Release Notes
- https://github.com/backstage/backstage/releases/tag/v1.54.6Patch, Release Notes
- https://github.com/backstage/backstage/security/advisories/GHSA-xvgh-hmx8-9xxfMitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.