CVE-2026-42280
Improper Permission Checking in Auth.js SDK
Auth0.js is a client-side JavaScript library for Auth0. From 8.11.0 to 9.32.0, 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. This vulnerability is fixed in 10.0.0.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Improper Permission Checking in Auth.js SDK
Auth0.js is a client-side JavaScript library for Auth0. From 8.11.0 to 9.32.0, 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. This vulnerability is fixed in 10.0.0.
- Record
CVE-2026-42280- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
EUVDEUVD-2026-32533
Auth0.js is a client-side JavaScript library for Auth0. From 8.11.0 to 9.32.0, 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. This vulnerability is fixed in 10.0.0.
- Record
EUVD-2026-32533- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-8qjv-jj2q-x832
Auth.js SDK has Improper Permission Checking
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.
- Record
GHSA-8qjv-jj2q-x832- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
NVD
Auth0.js is a client-side JavaScript library for Auth0. From 8.11.0 to 9.32.0, 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. This vulnerability is fixed in 10.0.0.
- Record
CVE-2026-42280- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
OSV
Improper Permission Checking in Auth.js SDK
Auth0.js is a client-side JavaScript library for Auth0. From 8.11.0 to 9.32.0, 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. This vulnerability is fixed in 10.0.0.
- Record
CVE-2026-42280- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
OSVGHSA-8qjv-jj2q-x832
Auth.js SDK has Improper Permission Checking
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.
- Record
GHSA-8qjv-jj2q-x832- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
Affected products
Affected packages
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-42280 is a high vulnerability (CVSS 7.1) in Auth0 Auth0.js, published May 6, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.21%, the 11th percentile. Fixed in auth0-js 10.0.0.