CVE-2026-106491
Published:October 06, 2026
Updated:October 09, 2026
Backstage is an open framework for building developer portals. Prior to 0.6.17, the @backstage/plugin-proxy-backend package is affected by improper input validation in proxy-backend. An authenticated Backstage user could craft a request URL that causes the proxy-backend to forward the request to a path outside the configured base path on the target server. This is limited to target servers already configured as proxy endpoints and requires Backstage authentication by default. This issue is fixed in version 0.6.17.
Affected Packages
https://github.com/backstage/backstage.git (GITHUB):
Affected version(s) >=v1.0.0 <v1.54.6Fix Suggestion:
Update to version v1.54.6@backstage/plugin-proxy-backend (NPM):
Affected version(s) >=0.0.0-nightly-2020972106 <0.6.17Fix Suggestion:
Update to version 0.6.17@backstage/plugin-proxy-backend (NPM):
Affected version(s) >=0.1.1-alpha.13 <0.6.17Fix Suggestion:
Update to version 0.6.17Related Resources (6)
Do you need more information?
Contact UsCVSS v4
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
LOW
Subsequent System Integrity
LOW
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.4
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
EPSS
Base Score:
0.27