CVE-2022-31027: OAuthenticator is an OAuth token library for the JupyerHub login handler. CILogonOAuthenticator is provided by the OAuthenticator package, and lets us...

Description

OAuthenticator is an OAuth token library for the JupyerHub login handler. CILogonOAuthenticator is provided by the OAuthenticator package, and lets users log in to a JupyterHub via CILogon. This is primarily used to restrict a JupyterHub only to users of a given institute. The allowed_idps configuration trait of CILogonOAuthenticator is documented to be a list of domains that indicate the institutions whose users are authorized to access this JupyterHub. This authorization is validated by ensuring that the *email* field provided to us by CILogon has a *domain* that matches one of the domains listed in `allowed_idps`.If `allowed_idps` contains `berkeley.edu`, you might expect only users with valid current credentials provided by University of California, Berkeley to be able to access the JupyterHub. However, CILogonOAuthenticator does *not* verify which provider is used by the user to login, only the email address provided. So a user can login with a GitHub account that has email set to `<something>@berkeley.edu`, and that will be treated exactly the same as someone logging in using the UC Berkeley official Identity Provider. The patch fixing this issue makes a *breaking change* in how `allowed_idps` is interpreted. It's no longer a list of domains, but configuration representing the `EntityID` of the IdPs that are allowed, picked from the [list maintained by CILogon](https://cilogon.org/idplist/). Users are advised to upgrade.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.43%

34.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-639

Affected Software

Vendor	Product	Versions
Jupyter	Oauthenticator	< 15.0.0

References

https://github.com/jupyterhub/oauthenticator/security/advisories/GHSA-r7v4-jwx9-wx43Third Party Advisory
https://github.com/jupyterhub/oauthenticator/security/advisories/GHSA-r7v4-jwx9-wx43Third Party Advisory

Timeline

Published: Jun 9, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2022-31027?

OAuthenticator is an OAuth token library for the JupyerHub login handler. CILogonOAuthenticator is provided by the OAuthenticator package, and lets users log in to a JupyterHub via CILogon. This is primarily used to restrict a JupyterHub only to users of a given institute. The allowed_idps configuration trait of CILogonOAuthenticator is documented to be a list of domains that indicate the institutions whose users are authorized to access this JupyterHub. This authorization is validated by ensuring that the *email* field provided to us by CILogon has a *domain* that matches one of the domains listed in `allowed_idps`.If `allowed_idps` contains `berkeley.edu`, you might expect only users with valid current credentials provided by University of California, Berkeley to be able to access the JupyterHub. However, CILogonOAuthenticator does *not* verify which provider is used by the user to login, only the email address provided. So a user can login with a GitHub account that has email set to `<something>@berkeley.edu`, and that will be treated exactly the same as someone logging in using the UC Berkeley official Identity Provider. The patch fixing this issue makes a *breaking change* in how `allowed_idps` is interpreted. It's no longer a list of domains, but configuration representing the `EntityID` of the IdPs that are allowed, picked from the [list maintained by CILogon](https://cilogon.org/idplist/). Users are advised to upgrade.

How severe is CVE-2022-31027?

CVE-2022-31027 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.43% probability of exploitation in the next 30 days.

How do I fix CVE-2022-31027?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.