CVE-2026-106503Backstage: Scaffolder action input authorization bypass
Updated under an hour ago ()
Does this affect you?
It affects backstage and 3 other products. Add what you run to find out whether that includes you.
EPSS puts the chance of exploitation in the next 30 days at 0.38%, higher than 31% of scored CVEs.
Do this next
Free account, 1 product
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
- 8.1 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- Weakness (CWE)
- CWE-178, CWE-284
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- 0.38% (percentile 31)
- Assigned by
- GitHub_M
- NVD analysis
- Analyzed
- Record last updated
- Oct 9, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
backstage backstage backstage:backstage (from the name) | before 1.49.6; from 1.50.0-next.0, < 1.50.5; from 1.51.0-next.0, < 1.54.6 | CNA record |
@backstage plugin-scaffolder-backend backstage:plugin_scaffolder_backend (from the name) | before 3.3.1; from 3.4.0, < 3.4.1; from 4.0.0, < 4.0.3; from 4.0.4, < 4.1.0 | CNA record |
linuxfoundation backstage/plugin-scaffolder-backend linuxfoundation:backstage/plugin-scaffolder-backend | before 3.3.1; from 3.4.0 before 3.4.1; from 4.0.0 before 4.0.3; from 4.0.4 before 4.1.0 | NVD |
linuxfoundation backstage linuxfoundation:backstage | before 1.49.6; from 1.50.0 before 1.50.5; from 1.51.0 before 1.54.6 | NVD |
References
- https://github.com/backstage/backstage/security/advisories/GHSA-hmp2-4m7g-22cvx-refsource-confirm, mitigation, vendor-advisory
- https://github.com/backstage/backstage/commit/11c1384c0649b8ab26391c6a4e4f34b80ab0d188x-refsource-misc, patch
- https://github.com/backstage/backstage/commit/a91ed72d540e80b62a73b39bb1563ff5018d52d1x-refsource-misc, patch
- https://github.com/backstage/backstage/commit/e307e4f487103d815e484291b3fda778ab9983bfx-refsource-misc, patch
- https://github.com/backstage/backstage/releases/tag/v1.49.6x-refsource-misc, patch, release-notes
- https://github.com/backstage/backstage/releases/tag/v1.50.5x-refsource-misc, patch, release-notes
- https://github.com/backstage/backstage/releases/tag/v1.54.6x-refsource-misc, patch, release-notes
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.