---
id: CVE-2026-106503
title: Backstage is an open framework for building developer portals
summary: >-
  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 wi…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-178
  - CWE-284
  - CWE-807
vendor: linuxfoundation
product: backstage/plugin-scaffolder-backend
affected:
  - backstage/plugin-scaffolder-backend < 3.3.1
  - 'backstage/plugin-scaffolder-backend >= 3.4.0, < 3.4.1'
  - 'backstage/plugin-scaffolder-backend >= 4.0.0, < 4.0.3'
  - 'backstage/plugin-scaffolder-backend >= 4.0.4, < 4.1.0'
  - backstage < 1.49.6
  - 'backstage >= 1.50.0, < 1.50.5'
  - 'backstage >= 1.51.0, < 1.54.6'
patched:
  - backstage/plugin-scaffolder-backend 4.1.0
  - backstage 1.54.6
published: '2026-10-06'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T14:37:56.910'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-106503'
references:
  - url: >-
      https://github.com/backstage/backstage/commit/11c1384c0649b8ab26391c6a4e4f34b80ab0d188
    label: security-advisories@github.com
  - url: >-
      https://github.com/backstage/backstage/commit/a91ed72d540e80b62a73b39bb1563ff5018d52d1
    label: security-advisories@github.com
  - url: >-
      https://github.com/backstage/backstage/commit/e307e4f487103d815e484291b3fda778ab9983bf
    label: security-advisories@github.com
  - url: 'https://github.com/backstage/backstage/releases/tag/v1.49.6'
    label: security-advisories@github.com
  - url: 'https://github.com/backstage/backstage/releases/tag/v1.50.5'
    label: security-advisories@github.com
  - url: 'https://github.com/backstage/backstage/releases/tag/v1.54.6'
    label: security-advisories@github.com
  - url: >-
      https://github.com/backstage/backstage/security/advisories/GHSA-hmp2-4m7g-22cv
    label: security-advisories@github.com
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-106503'
  - url: 'https://github.com/advisories/GHSA-hmp2-4m7g-22cv'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-106503.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-106503'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2547234'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-106503'
  - url: 'https://access.redhat.com/errata/RHSA-2026:86675'
tags:
  - nvd
  - cve.org
  - ghsa
  - npm
  - csaf
  - vex
  - red-hat
epss: 0.00492
epssPercentile: 0.42481
aliases:
  - GHSA-hmp2-4m7g-22cv
ecosystem: npm
ingestedAt: '2026-10-06T22:23:15.967Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-09T01:55:45.447568Z'
---

## Overview

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.

## Affected

- `backstage/plugin-scaffolder-backend < 3.3.1`
- `backstage/plugin-scaffolder-backend >= 3.4.0, < 3.4.1`
- `backstage/plugin-scaffolder-backend >= 4.0.0, < 4.0.3`
- `backstage/plugin-scaffolder-backend >= 4.0.4, < 4.1.0`
- `backstage < 1.49.6`
- `backstage >= 1.50.0, < 1.50.5`
- `backstage >= 1.51.0, < 1.54.6`

## Remediation

Upgrade past the affected range:

- `backstage/plugin-scaffolder-backend 4.1.0`
- `backstage 1.54.6`

## Package advisory (CVE-2026-106503)

Affected packages:

- `@backstage/plugin-scaffolder-backend < 3.3.1`
- `@backstage/plugin-scaffolder-backend >= 3.4.0, < 3.4.1`
- `@backstage/plugin-scaffolder-backend >= 4.0.0, < 4.0.3`
- `@backstage/plugin-scaffolder-backend >= 4.0.4, < 4.1.0`

Patched in:

- `@backstage/plugin-scaffolder-backend 3.3.1`
- `@backstage/plugin-scaffolder-backend 3.4.1`
- `@backstage/plugin-scaffolder-backend 4.0.3`
- `@backstage/plugin-scaffolder-backend 4.1.0`

Source: https://github.com/advisories/GHSA-hmp2-4m7g-22cv

## Vendor advisories

- **RHSA-2026:86675** · Red Hat · fixed in: Red Hat Ansible Automation Platform 2.2 · released 2026-10-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:86675)
- **Red Hat VEX** · Important · affected: Red Hat Developer Hub, Self-service automation portal 2 · no fix planned: Red Hat Developer Hub, Self-service automation portal 2 · updated 2026-10-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-106503.json)