Vulnerability in @backstage/plugin-scaffolder-backend (CVE-2026-106503)
Summary
Vulnerability in @backstage/plugin-scaffolder-backend (CVE-2026-106503). Confidential information can be exposed externally. Mitigation: upgrade to 4.1.0 or later.
Original description
The description as published by the source.
Impact
An authenticated user with access to affected Scaffolder templates could bypass configured action restrictions. Depending on integration credentials, this could grant unauthorized access to repositories and related source-control resources.
Patches
Patched in @backstage/plugin-scaffolder-backend version 4.1.0
Workarounds
- Restrict affected Scaffolder actions to trusted users and configure source-control integrations with least-privilege credentials.
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-2026-106503 has been found in @backstage/plugin-scaffolder-backend.
Confidential information can be exposed externally. CVSS score: 8.1/10.
What to do: upgrade @backstage/plugin-scaffolder-backend to 4.1.0 or later.
If unsure, ask your IT team or search "@backstage/plugin-scaffolder-backend CVE-2026-106503" on the vendor's site.
CVE-2026-106503 (@backstage/plugin-scaffolder-backend) — CWE-178 / CVSS v3 8.1
Attack vector: remote (network-reachable) / no user interaction
Patched: 4.1.0 — apply immediately
Workaround: - Restrict affected Scaffolder actions to trusted users and configure source-control integrations with least-privilege credentials.
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.
A vulnerability (CWE-178) exists in @backstage/plugin-scaffolder-backend.
Check the vendor advisory for the affected versions of @backstage/plugin-scaffolder-backend.
Severity: High (CVSS 8.1/10). Confidential information can be exposed externally.
Update to 4.1.0.
Workaround: - Restrict affected Scaffolder actions to trusted users and configure source-control integrations with least-privilege credentials.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r '@backstage/plugin-scaffolder-backend' . 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-scaffolder-backend' . | 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-scaffolder-backend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
- Restrict affected Scaffolder actions to trusted users and configure source-control integrations with least-privilege credentials.パッチが適用されるまでの応急処置として、- Restrict affected Scaffolder actions to trusted users and configure source-control integrations with least-privilege credentials. 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-scaffolder-backend to 4.1.0ステージング環境で 4.1.0 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。
Affected packages
References
- patch security-advisories@github.com
- patch security-advisories@github.com
- patch security-advisories@github.com
- patch security-advisories@github.com
- patch security-advisories@github.com
- patch security-advisories@github.com
- patch security-advisories@github.com
- web nvd.nist.gov
- web github.com