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OpenAdvisories
High · 8.8 CVE-2026-33175 EUVD-2026-18878GHSA-rrvg-cxh4-qhrvPYSEC-2026-2238

OAuthenticator: Authentication Bypass in Auth0OAuthenticator via Unverified Email Claims

Published Apr 3, 2026 · Updated Apr 7, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
jupyterhub oauthenticator < 17.4.0 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

Wolfi

ReleasePackageFixed inAdvisory
Wolfi rolling py3.10-oauthenticator +3 17.4.0-r0 —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI oauthenticator < 17.4.0 17.4.0 GHSA-rrvg-cxh4-qhrv

References