CVE-2026-33175

HIGH

OAuthenticator: Authentication Bypass in Auth0OAuthenticator via Unverified Email Claims

Title source: cna

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.

References (3)

[X_Refsource_Confirm] https://github.com/jupyterhub/oauthenticator/security/advisories/GHSA-rrvg-cxh4-qhrv

[X_Refsource_Misc] https://github.com/jupyterhub/oauthenticator/commit/f0c7002dc36e41efae0f674033cf7888a21d96f9

View Writeup ZIP pw:eip

[X_Refsource_Misc] https://github.com/jupyterhub/oauthenticator/releases/tag/17.4.0

Scores

CVSS v3 8.8

EPSS 0.0011

EPSS Percentile 28.8%

Attack Vector NETWORK

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

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact total

Details

CWE

CWE-287 CWE-290

Status published

Products (3)

jupyter/oauthenticator < 17.4.0

jupyterhub/oauthenticator < 17.4.0

pypi/oauthenticator 0 - 17.4.0PyPI

Published Apr 03, 2026

Tracked Since Apr 04, 2026