Authentication Bypass in @backstage/plugin-auth-backend-module-oidc-provider (CVE-2026-106488)
Summary
Authentication bypass in @backstage/plugin-auth-backend-module-oidc-provider (CVE-2026-106488). Confidential information can be exposed externally. Mitigation: upgrade to 0.4.20 or later.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-106488 has been found in @backstage/plugin-auth-backend-module-oidc-provider.
Confidential information can be exposed externally. CVSS score: 8.1/10.
What to do: upgrade @backstage/plugin-auth-backend-module-oidc-provider to 0.4.20 or later.
If unsure, ask your IT team or search "@backstage/plugin-auth-backend-module-oidc-provider CVE-2026-106488" on the vendor's site.
CVE-2026-106488 (@backstage/plugin-auth-backend-module-oidc-provider) — CWE-287 / CVSS v3 8.1
Attack vector: remote (network-reachable) / no user interaction
Patched: 0.4.20 — apply immediately
Workaround: - Disable email-based sign-in resolution for the OIDC provider, or require the identity provider to verify email addresses before allowing sign-in.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Authentication bypass (CWE-287) exists in @backstage/plugin-auth-backend-module-oidc-provider.
Check the vendor advisory for the affected versions of @backstage/plugin-auth-backend-module-oidc-provider.
Severity: High (CVSS 8.1/10). Confidential information can be exposed externally.
Update to 0.4.20.
Workaround: - Disable email-based sign-in resolution for the OIDC provider, or require the identity provider to verify email addresses before allowing sign-in.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r '@backstage/plugin-auth-backend-module-oidc-provider' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r '@backstage/plugin-auth-backend-module-oidc-provider' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
@backstage/plugin-auth-backend-module-oidc-providerを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
- Disable email-based sign-in resolution for the OIDC provider, or require the identity provider to verify email addresses before allowing sign-in.パッチが適用されるまでの応急処置として、- Disable email-based sign-in resolution for the OIDC provider, or require the identity provider to verify email addresses before allowing sign-in. を実施。回避策の副作用 (機能低下) を確認した上で。
-
3Apply patch patch
Upgrade @backstage/plugin-auth-backend-module-oidc-provider to 0.4.20ステージング環境で 0.4.20 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。