Description
Backstage is an open framework for building developer portals. Prior to 0.27.1, a Server-Side Request Forgery (SSRF) vulnerability exists in @backstage/plugin-auth-backend when auth.experimentalClientIdMetadataDocuments.enabled is set to true. The CIMD
metadata fetch validates the initial client_id hostname against private IP ranges but does not apply the same validation after HTTP redirects. The practical impact is limited. The attacker cannot read the response body from the internal request, cannot control request headers or method, and the feature must be explicitly enabled via an experimental flag that is off by default. Deployments that restrict allowedClientIdPatterns to specific trusted domains are not affected. Patched in @backstage/plugin-auth-backend version 0.27.1.
Published: 2026-03-12
Score: 1.7 Low
EPSS: < 1% Very Low
KEV: No
Impact: Server-Side Request Forgery
Action: Patch
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-qp4c-xg64-7c6x @backstage/plugin-auth-backend: SSRF in experimental CIMD metadata fetch
History

Wed, 15 Apr 2026 21:30:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 0.0, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:N'}

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}


Wed, 15 Apr 2026 21:00:00 +0000

Type Values Removed Values Added
Metrics cvssV4_0

{'score': 1.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U'}


Mon, 13 Apr 2026 14:30:00 +0000

Type Values Removed Values Added
First Time appeared Linuxfoundation
Linuxfoundation backstage
CPEs cpe:2.3:a:linuxfoundation:backstage:*:*:*:*:*:*:*:*
Vendors & Products Linuxfoundation
Linuxfoundation backstage

Fri, 13 Mar 2026 10:00:00 +0000

Type Values Removed Values Added
First Time appeared Backstage
Backstage plugin-auth-backend
Vendors & Products Backstage
Backstage plugin-auth-backend

Fri, 13 Mar 2026 00:15:00 +0000


Thu, 12 Mar 2026 21:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 12 Mar 2026 19:00:00 +0000

Type Values Removed Values Added
Description Backstage is an open framework for building developer portals. Prior to 0.27.1, a Server-Side Request Forgery (SSRF) vulnerability exists in @backstage/plugin-auth-backend when auth.experimentalClientIdMetadataDocuments.enabled is set to true. The CIMD metadata fetch validates the initial client_id hostname against private IP ranges but does not apply the same validation after HTTP redirects. The practical impact is limited. The attacker cannot read the response body from the internal request, cannot control request headers or method, and the feature must be explicitly enabled via an experimental flag that is off by default. Deployments that restrict allowedClientIdPatterns to specific trusted domains are not affected. Patched in @backstage/plugin-auth-backend version 0.27.1.
Title @backstage/plugin-auth-backend: SSRF in experimental CIMD metadata fetch
Weaknesses CWE-918
References
Metrics cvssV3_1

{'score': 0, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:N'}


Subscriptions

Backstage Plugin-auth-backend
Linuxfoundation Backstage
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-04-15T20:46:50.517Z

Reserved: 2026-03-11T14:47:05.683Z

Link: CVE-2026-32236

cve-icon Vulnrichment

Updated: 2026-03-12T20:38:13.637Z

cve-icon NVD

Status : Modified

Published: 2026-03-12T19:16:18.867

Modified: 2026-04-15T21:17:26.827

Link: CVE-2026-32236

cve-icon Redhat

Severity :

Publid Date: 2026-03-12T18:37:11Z

Links: CVE-2026-32236 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-04-16T03:00:09Z

Weaknesses