CVE-2026-106503

high

Backstage is an open framework for building developer portals.

Vendor / product: Linuxfoundation — backstage\/plugin-scaffolder-backend

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

8.1 (CVSS v3.1)

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Severity source: NVD CVSS v3.1 (security-advisories@github.com)

Timeline (UTC)

Published: 2026-10-06 22:17

Modified: 2026-10-13 14:37

NVD status: Analyzed

Last synced 2 days ago

Verified against the source API 2026-10-27 06:58 UTC

Exploitation

Not listed in CISA KEV (as of last catalog sync)

Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

linuxfoundation / backstage\/plugin-scaffolder-backend <3.3.1, ≥3.4.0 <3.4.1, ≥4.0.0 <4.0.3, ≥4.0.4 <4.1.0

linuxfoundation / backstage <1.49.6, ≥1.50.0 <1.50.5, ≥1.51.0 <1.54.6

Weakness classification (CWE)

CWE-178 CWE-284

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

Vendor advisory: https://github.com/backstage/backstage/security/advisories/GHSA-hmp2-4m7g-22cv

Patch / mitigation: https://github.com/backstage/backstage/commit/11c1384c0649b8ab26391c6a4e4f34b80ab0d188

Patch / mitigation: https://github.com/backstage/backstage/commit/a91ed72d540e80b62a73b39bb1563ff5018d52d1

Patch / mitigation: https://github.com/backstage/backstage/commit/e307e4f487103d815e484291b3fda778ab9983bf

Patch / mitigation: https://github.com/backstage/backstage/releases/tag/v1.49.6

Patch / mitigation: https://github.com/backstage/backstage/releases/tag/v1.50.5

Patch / mitigation: https://github.com/backstage/backstage/releases/tag/v1.54.6

Patch / mitigation: https://github.com/backstage/backstage/security/advisories/GHSA-hmp2-4m7g-22cv

References

https://github.com/backstage/backstage/commit/11c1384c0649b8ab26391c6a4e4f34b80ab0d188 security-advisories@github.com
https://github.com/backstage/backstage/commit/a91ed72d540e80b62a73b39bb1563ff5018d52d1 security-advisories@github.com
https://github.com/backstage/backstage/commit/e307e4f487103d815e484291b3fda778ab9983bf security-advisories@github.com
https://github.com/backstage/backstage/releases/tag/v1.49.6 security-advisories@github.com
https://github.com/backstage/backstage/releases/tag/v1.50.5 security-advisories@github.com
https://github.com/backstage/backstage/releases/tag/v1.54.6 security-advisories@github.com
https://github.com/backstage/backstage/security/advisories/GHSA-hmp2-4m7g-22cv security-advisories@github.com

Data sources

NVD CVE API 2.0 — fetched 2026-10-27 06:58 UTC · record ↗

Learn the basics

Understanding CVEs and CVSS Scores

CVE-2026-106503

Affected products

Weakness classification (CWE)

Mitigation & advisories

References

Data sources

Learn the basics

Related CVEs