cvedb.io
CVE-2021-41194
CRITICAL · CVSS 9.1
EPSS exploitation probability: 0%
Published 2021-10-28T20:15:07.680 · Last modified 2026-06-17T04:08:04.187

Summary

FirstUseAuthenticator is a JupyterHub authenticator that helps new users set their password on their first login to JupyterHub. When JupyterHub is used with FirstUseAuthenticator, a vulnerability in versions prior to 1.0.0 allows unauthorized access to any user's account if `create_users=True` and the username is known or guessed. One may upgrade to version 1.0.0 or apply a patch manually to mitigate the vulnerability. For those who cannot upgrade, there is no complete workaround, but a partial mitigation exists. One can disable user creation with `c.FirstUseAuthenticator.create_users = False`, which will only allow login with fully normalized usernames for already existing users prior to jupyterhub-firstuserauthenticator 1.0.0. If any users have never logged in with their normalized usern

Affected products

jupyterhub — first_use_authenticator

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.