CVE-2026-33175: CWE-287: Improper Authentication in jupyterhub oauthenticator
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.
AI Analysis
Technical Summary
OAuthenticator, used with JupyterHub to integrate OAuth2 identity providers, contained an authentication bypass vulnerability before version 17.4.0. Specifically, when email is used as the username_claim, an attacker possessing an unverified email address on an Auth0 tenant could bypass authentication and gain access to JupyterHub. This grants control over usernames and can lead to account takeover. The vulnerability is tracked as CVE-2026-33175 with a CVSS 3.1 score of 8.8 (network attack vector, low attack complexity, requires low privileges, no user interaction, impacts confidentiality, integrity, and availability). The issue has been patched in oauthenticator version 17.4.0.
Potential Impact
Successful exploitation allows attackers with unverified email addresses on an Auth0 tenant to bypass authentication and log into JupyterHub instances using oauthenticator with email as username_claim. This can lead to unauthorized access and account takeover, impacting confidentiality, integrity, and availability of the affected system.
Mitigation Recommendations
Upgrade oauthenticator to version 17.4.0 or later, where this authentication bypass vulnerability has been fixed. No other mitigation guidance is provided or necessary as the issue is resolved by this patch.
CVE-2026-33175: CWE-287: Improper Authentication in jupyterhub oauthenticator
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
OAuthenticator, used with JupyterHub to integrate OAuth2 identity providers, contained an authentication bypass vulnerability before version 17.4.0. Specifically, when email is used as the username_claim, an attacker possessing an unverified email address on an Auth0 tenant could bypass authentication and gain access to JupyterHub. This grants control over usernames and can lead to account takeover. The vulnerability is tracked as CVE-2026-33175 with a CVSS 3.1 score of 8.8 (network attack vector, low attack complexity, requires low privileges, no user interaction, impacts confidentiality, integrity, and availability). The issue has been patched in oauthenticator version 17.4.0.
Potential Impact
Successful exploitation allows attackers with unverified email addresses on an Auth0 tenant to bypass authentication and log into JupyterHub instances using oauthenticator with email as username_claim. This can lead to unauthorized access and account takeover, impacting confidentiality, integrity, and availability of the affected system.
Mitigation Recommendations
Upgrade oauthenticator to version 17.4.0 or later, where this authentication bypass vulnerability has been fixed. No other mitigation guidance is provided or necessary as the issue is resolved by this patch.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-03-17T22:16:36.719Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69d03c020a160ebd926055e1
Added to database: 4/3/2026, 10:15:30 PM
Last enriched: 4/11/2026, 9:12:00 AM
Last updated: 5/21/2026, 5:34:08 PM
Views: 78
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