CVE-2026-106503
Published:October 06, 2026
Updated:October 13, 2026
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 Packages
https://github.com/backstage/backstage.git (GITHUB):
Affected version(s) >=v1.13.1 <v1.49.6Fix Suggestion:
Update to version v1.49.6https://github.com/backstage/backstage.git (GITHUB):
Affected version(s) >=v1.51.0 <v1.54.6Fix Suggestion:
Update to version v1.54.6https://github.com/backstage/backstage.git (GITHUB):
Affected version(s) >=v1.50.0 <v1.50.5Fix Suggestion:
Update to version v1.50.5@backstage/plugin-scaffolder-backend (NPM):
Affected version(s) >=3.4.0 <3.4.1Fix Suggestion:
Update to version 3.4.1@backstage/plugin-scaffolder-backend (NPM):
Affected version(s) >=4.0.0 <4.1.0Fix Suggestion:
Update to version 4.1.0@backstage/plugin-scaffolder-backend (NPM):
Affected version(s) >=0.0.0-nightly-2020972106 <3.3.1Fix Suggestion:
Update to version 3.3.1@backstage/plugin-scaffolder-backend (NPM):
Affected version(s) >=4.0.4 <4.1.0Fix Suggestion:
Update to version 4.1.0@backstage/plugin-scaffolder-backend (NPM):
Affected version(s) >=4.0.0 <4.0.3Fix Suggestion:
Update to version 4.0.3@backstage/plugin-scaffolder-backend (NPM):
Affected version(s) >=3.0.0 <3.3.1Fix Suggestion:
Update to version 3.3.1Related Resources (10)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.6
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
8.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
EPSS
Base Score:
0.36