CVE-2026-33175

OAuthenticator: Authentication Bypass in Auth0OAuthenticator via Unverified Email Claims

Published Apr 3, 2026 CVSS 3.1 · 8.8 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-rrvg-cxh4-qhrv Auth0OAuthenticator has an Authentication Bypass via Unverified Email Claims
History
Type Values Removed Values Added
First Time appeared Jupyter
Jupyter oauthenticator
CPEs cpe:2.3:a:jupyter:oauthenticator:*:*:*:*:*:*:*:*
Vendors & Products Jupyter
Jupyter oauthenticator
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Jupyterhub
Jupyterhub oauthenticator
Vendors & Products Jupyterhub
Jupyterhub oauthenticator
Type Values Removed Values Added
Description 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.
Title OAuthenticator: Authentication Bypass in Auth0OAuthenticator via Unverified Email Claims
Weaknesses CWE-287
CWE-290
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Apr 7, 2026, 4:01 PM
Reserved
Mar 17, 2026, 10:16 PM
Status
Analyzed
Published
Apr 3, 2026, 10:16 PM
Modified
Jul 24, 2026, 10:10 PM