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.

Project Subscriptions

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-wqvh-63mv-9w92 @backstage/plugin-auth-backend: OAuth redirect URI allowlist bypass
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

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

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


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, 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.
Title @backstage/plugin-auth-backend: OAuth redirect URI allowlist bypass
Weaknesses CWE-601
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-03-12T20:46:46.618Z

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

Link: CVE-2026-32235

cve-icon Vulnrichment

Updated: 2026-03-12T20:38:14.902Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-03-12T19:16:17.443

Modified: 2026-03-12T21:07:53.427

Link: CVE-2026-32235

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-03-12T18:35:06Z

Links: CVE-2026-32235 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses