CVE-2026-32235
CVE-2026-32235 is a medium-severity vulnerability in Linuxfoundation Backstage with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-601.
Key facts
- Severity: Medium (CVSS 3.x base score 5.9)
- EPSS exploit prediction: 0% (4th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-11671
- Weakness: CWE-601
- Affected product: Linuxfoundation Backstage
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-32235?
- 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.
- How severe is CVE-2026-32235?
- CVE-2026-32235 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity low, and availability none.
- Is CVE-2026-32235 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-32235?
- CVE-2026-32235 affects Linuxfoundation Backstage. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2026-32235?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2026-32235 have an EU (EUVD) identifier?
- Yes. CVE-2026-32235 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-11671.
- When was CVE-2026-32235 published?
- CVE-2026-32235 was published on 2026-03-12 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:linuxfoundation:backstage:*:*:*:*:*:*:*:*
More vulnerabilities in Linuxfoundation Backstage
- CVE-2021-43783 — High (CVSS 8.5): @backstage/plugin-scaffolder-backend is the backend for the default Backstage software templates. In affected versions…
- CVE-2023-35926 — High (CVSS 8.0): Backstage is an open platform for building developer portals. The Backstage scaffolder-backend plugin uses a templating…
- CVE-2026-25153 — High (CVSS 7.7): Backstage is an open framework for building developer portals, and @backstage/plugin-techdocs-node provides common…
- CVE-2026-32236 — High (CVSS 7.5): Backstage is an open framework for building developer portals. Prior to 0.27.1, a Server-Side Request Forgery (SSRF)…
- CVE-2021-41151 — Medium (CVSS 6.8): Backstage is an open platform for building developer portals. In affected versions A malicious actor could read…
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Other CWE-601 (Open Redirect) vulnerabilities
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- CVE-2020-36912 — Critical (CVSS 9.8): Plexus anblick Digital Signage Management 3.1.13 contains an open redirect vulnerability in the 'PantallaLogin' script…
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- CVE-2024-22891 — Critical (CVSS 9.8): Nteract v.0.28.0 was discovered to contain a remote code execution (RCE) vulnerability via the Markdown link.