Bug 2447090 (CVE-2026-32236)

Summary:	CVE-2026-32236 @backstage/plugin-auth-backend: @backstage/plugin-auth-backend: SSRF in experimental CIMD metadata fetch
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	unspecified	CC:	abarbaro, alizardo, dschmidt, erezende, jchui, jhe, jlanda, kshier, ktsao, nboldt, psrna, simaishi, smcdonal, stcannon, teagle, yguenane
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A server side request forgery flaw has been discovered in the npm @backstage/plugin-auth-backend package. 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.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
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Description OSIDB Bzimport 2026-03-12 19:02:16 UTC

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.