CVE-2026-106503CWE-178CWE-284broken-access-control

CVE-2026-106503

High · published October 7, 2026

CVSS v3.1
8.1
EPSS
0%
Percentile
31.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.1 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00382 · 31.0th percentile
Weaknesses
CWE-178 · Improper Handling of Case Sensitivity; CWE-284 · Improper Access Control
Published
2026-10-07T02:17Z
Affected products (7)
ProductVersionsFixed in
linuxfoundation/backstage\/plugin-scaffolder-backend< 3.3.13.3.1
linuxfoundation/backstage\/plugin-scaffolder-backend≥ 3.4.0, < 3.4.13.4.1
linuxfoundation/backstage\/plugin-scaffolder-backend≥ 4.0.0, < 4.0.34.0.3
linuxfoundation/backstage\/plugin-scaffolder-backend≥ 4.0.4, < 4.1.04.1.0
linuxfoundation/backstage< 1.49.61.49.6
linuxfoundation/backstage≥ 1.50.0, < 1.50.51.50.5
linuxfoundation/backstage≥ 1.51.0, < 1.54.61.54.6
References (7)
EPSS history
Timeline
  • 08 OCT 03:27Z
    EPSS moved — → 0%
    epss
  • 06 OCT 21:37Z
    Backstage: Scaffolder action input authorization bypass
    cvelistv5