All vulnerabilities
CVE-2026-106488GHSA-826h-28h9-65hg

Backstage: Improper authentication in the OIDC provider

backstage @backstage/plugin-auth-backend-module-oidc-providernpmLibraries & packages
Open in ThreatlineRecord JSON
CVSS
8.1High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.28%Chance of exploitation activity in the next 30 days, higher than 19% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in0.4.20Fixed versionGitHub
Published6 Oct 2026Updated 7 Oct 2026CVE List

What fixes it

  • 0.4.20@backstage/plugin-auth-backend-module-oidc-provider, npmGitHubnpm install @backstage/plugin-auth-backend-module-oidc-provider@0.4.20

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

Impact

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.

Patches

Patched in @backstage/plugin-auth-backend-module-oidc-provider version 0.4.20.

Workarounds

  • Disable email-based sign-in resolution for the OIDC provider, or require the identity provider to verify email addresses before allowing sign-in.

Text from GitHub Advisory Database

Affected versions 4

  • @backstage/plugin-auth-backend-module-oidc-provider, npm< 0.4.20GitHub
  • backstageaffected: < 1.54.6CVE List
  • plugin-auth-backend-module-oidc-provideraffected: < 0.4.20CVE List
  • @backstage/plugin-auth-backend-module-oidc-provider, npmfrom first release, fixed in 0.4.20OSV

References 5