CVE-2026-33175 HIGH

CVE-2026-33175: OAuthenticator: Authentication Bypass in Auth0OAuthenticator via Unverified Email Claims

Vendor Jupyterhub
Product oauthenticator
Weakness CWE-287 · Improper authentication
Published April 3, 2026
Last update April 7, 2026
View on NVD All CVEs

CVSS base score

8.8/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

April 3, 2026 CVE published
April 7, 2026 Record updated