Authorization Flaw in auth0-js (CVE-2026-42280)
Summary
Vulnerability in auth0-js (CVE-2026-42280). Confidential information can be exposed externally. Mitigation: upgrade to 10.0.0 or later.
Original description
The description as published by the source.
Description
Under specific preconditions, the Auth0.js SDK may improperly return user profile information using a valid access token when a specifically crafted invalid ID token is provided.
Am I Affected?
Users are affected if they meet each of the following preconditions:
- Applications built using Auth0.js version between 8.11.0 and 9.32.0
- The application’s access control relies on rules defined in Auth0 Actions.
Affected product and versions
auth0.js SDK v8.11.0 to v9.32.0
Resolution
Upgrade auth0/auth0.js to v10.0.0 or greater.
Acknowledgements
Okta would like to thank Quan Le (@aleister1102) for their discovery and responsible disclosure.
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-2026-42280 has been found in auth0-js.
Confidential information can be exposed externally. CVSS score: 7.1/10.
What to do: upgrade auth0-js to 10.0.0 or later.
If unsure, ask your IT team or search "auth0-js CVE-2026-42280" on the vendor's site.
CVE-2026-42280 (auth0-js) — CWE-863 / CVSS v3 7.1
Attack vector: remote (network-reachable) / no user interaction
Patched: 10.0.0 — apply immediately
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.
Incorrect authorization (CWE-863) exists in auth0-js.
Check the vendor advisory for the affected versions of auth0-js.
Severity: High (CVSS 7.1/10). Confidential information can be exposed externally.
Update to 10.0.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'auth0-js' . 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 'auth0-js' . | 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
auth0-jsを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade auth0-js to 10.0.0ステージング環境で 10.0.0 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。
-
3Post-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
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com