CVE-2026-106488 Backstage: Improper authentication in the OIDC provider
Authenticated users can assume other identities via unverified emails in OIDC, gaining unauthorized access and permissions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-106488?
CVE-2026-106488 is a high-severity authentication bypass vulnerability in Linuxfoundation Backstage, published on 6 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Backstage is an open framework for building developer portals. Prior to 0.4.20, the @backstage/plugin-auth-backend-module-oidc-provider package is affected by improper authentication in the oidc provider. Deployments using OIDC email-based identity resolution with a provider that permits unverified email addresses may allow an authenticated provider user to assume another catalog identity. This may grant access and permissions associated with that user. No direct availability impact is demonstrated. This issue is fixed in version 0.4.20.
Weakness: CWE-287
Which versions are affected by CVE-2026-106488?
2 open source packages ship an affected version, including @backstage/plugin-auth-backend-module-oidc-provider. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
@backstage/plugin-auth-backend-module-oidc-provider npm | All versions | 0.4.20 |
@backstage/plugin-auth-backend-module-oidc-provider npm | All versions | 0.4.20 |
Products include Linuxfoundation Backstage, Linuxfoundation Backstage\/Plugin-Auth-Backend-Module-Oidc-Provider.
How do I fix CVE-2026-106488?
Upgrade @backstage/plugin-auth-backend-module-oidc-provider to 0.4.20 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-106488 being exploited?
There is no known exploitation of CVE-2026-106488 in the wild and no public exploit code.
Other vulnerabilities in Linuxfoundation Backstage
- CVE-2026-106501 Backstage: Sensitive information exposure in Scaffolder
- CVE-2026-106558 Backstage: Improper validation of TechDocs MkDocs configuration
- CVE-2026-88064 Backstage: Improper input validation in TechDocs MkDocs configuration
- CVE-2026-106459 Backstage: Improper input validation in Sentry scaffolder actions
- CVE-2026-106486 Backstage: Improper filesystem validation in Bitbucket pull-request scaffolder actions
Sources
Also known as GHSA-826h-28h9-65hg.