CVE-2022-31027: OAuthenticator allows unauthorized access to JupyterHub
Summary
CVE-2022-31027: OAuthenticator is an OAuth token library for the JupyerHub login handler. Affects oauthenticator versions < 15.0.0. Fixed in 15.0.0. How to fix ↓
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Background
OAuthenticator is an OAuth token library for the JupyterHub login handler. It provides authentication and authorization capabilities for JupyterHub, allowing users to log in using various identity providers. CILogonOAuthenticator, a component of OAuthenticator, enables users to log in to JupyterHub via CILogon, restricting access to users from specific institutions. This is achieved by validating the email domain against a list of allowed domains. However, a vulnerability in CILogonOAuthenticator allows unauthorized access to JupyterHub by bypassing the domain validation check.
Vulnerability Detail
The vulnerability in CILogonOAuthenticator lies in its failure to verify the identity provider used by the user to log in. Instead of checking the provider, it solely relies on the email address provided. This means that a user can log in with a GitHub account that has an email address ending with the domain of an allowed institution, even if they are not affiliated with that institution. For example, a user with an email address like <something>@berkeley.edu can gain access to the JupyterHub, even if they do not have valid credentials from the University of California, Berkeley. This vulnerability poses a significant risk as it allows unauthorized users to access sensitive resources and potentially compromise the system.
How To Fix
Latest published version: 17.4.0 as of 22 Oct 2026
pip install --upgrade "oauthenticator==17.4.0"Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
15.0.0
This is the first release that contains the fix.
pip install --upgrade "oauthenticator==15.0.0"Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
There is no known workaround for this vulnerability. It is recommended to apply the patch provided in the updated version of OAuthenticator.
Conclusion
The vulnerability in CILogonOAuthenticator allows unauthorized access to JupyterHub, posing a significant risk to the security of the system. Users are strongly advised to upgrade to the latest version of OAuthenticator and apply the provided patch. For further support and assistance in vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for oauthenticator →
FAQ
OAuthenticator is an OAuth token library for the JupyterHub login handler. It provides authentication and authorization capabilities for JupyterHub, allowing users to log in using various identity providers.
CILogonOAuthenticator is a component of OAuthenticator that enables users to log in to JupyterHub via CILogon, restricting access to users from specific institutions.
The vulnerability in CILogonOAuthenticator allows unauthorized access to JupyterHub by bypassing the domain validation check. It fails to verify the identity provider used by the user and solely relies on the email address provided.
The vulnerability allows unauthorized users to access JupyterHub, potentially compromising sensitive resources and the overall system security.
To fix this vulnerability, upgrade to OAuthenticator version 15.0.0 or later, which includes the necessary patch to address the issue.
References
Related vulnerabilities
Recent vulnerabilities recorded for oauthenticator.
