Cloudanix VulnDB

CVE-2026-32235

Medium · 5.9

CVSS

5.9

EPSS

0.2%

Published

Mar 12, 2026

CISA due date

—

The record

Backstage is an open framework for building developer portals. Prior to 0.27.1, the experimental OIDC provider in @backstage/plugin-auth-backend is vulnerable to a redirect URI allowlist bypass. Instances that have enabled experimental Dynamic Client Registration or Client ID Metadata Documents and configured allowedRedirectUriPatterns are affected. A specially crafted redirect URI can pass the allowlist validation while resolving to an attacker-controlled host. If a victim approves the resulting OAuth consent request, their authorization code is sent to the attacker, who can exchange it for a valid access token. This requires victim interaction and that one of the experimental features is explicitly enabled, which is not the default. This vulnerability is fixed in 0.27.1.

Affected packages

Ecosystem Package Introduced Fixed
npm @backstage/plugin-auth-backend 0 0.27.1

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