CVE-2026-33175
OAuthenticator: Authentication Bypass in Auth0OAuthenticator via Unverified Email Claims
CVSS Score
8.8
EPSS Score
0.1%
EPSS Percentile
27th
OAuthenticator is software that allows OAuth2 identity providers to be plugged in and used with JupyterHub. Prior to version 17.4.0, an authentication bypass vulnerability in oauthenticator allows an attacker with an unverified email address on an Auth0 tenant to login to JupyterHub. When email is used as the usrname_claim, this gives users control over their username and the possibility of account takeover. This issue has been patched in version 17.4.0.
| CWE | CWE-287 CWE-290 |
| Vendor | jupyterhub |
| Product | oauthenticator |
| Published | Apr 3, 2026 |
| Last Updated | Apr 7, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
jupyterhub / oauthenticator
< 17.4.0