Base class whitelist configuration ignored in OAuthenticator
Impact
What goes wrong?
The deprecated (in jupyterhub 1.2) configuration Authenticator.whitelist, which should be transparently mapped to Authenticator.allowed_users with a warning, is instead ignored by OAuthenticator classes, resulting in the same behavior as if this configuration has not been set. If this is the only mechanism of authorization restriction (i.e. no group or team restrictions in configuration) then all authenticated users will be allowed. Provider-based restrictions, including deprecated values such as GitHubOAuthenticator.org_whitelist are not affected.
Who is impacted?
All users of OAuthenticator 0.12.0 and 0.12.1 with JupyterHub 1.2 (JupyterHub Helm chart 0.10.0-0.10.5) who use the admin.whitelist.users configuration in the jupyterhub helm chart or the c.Authenticator.whitelist configuration directly. Users of other deprecated configuration, e.g. c.GitHubOAuthenticator.team_whitelist are not affected.
If you see a log line like this and expect a specific list of allowed usernames:
[I 2020-11-27 16:51:54.528 JupyterHub app:1717] Not using allowed_users. Any authenticated user will be allowed.you are likely affected.
Patches
- Replacing deprecated
c.Authenticator.whitelist = ...withc.Authenticator.allowed_users = ...avoids the issue. - Update oauthenticator to 0.12.2
- Update jupyterhub helm chart to 0.10.6
If any users have been authorized during this time who should not have been, they must be deleted via the API or admin interface, per the documentation.
Workarounds
Replacing c.Authenticator.whitelist = ... with c.Authenticator.allowed_users = ... avoids the issue.
In the jupyterhub helm chart prior to 0.10.6, this can be done via hub.extraConfig:
auth:
allowedUsers:
- user1
- user2
hub:
extraConfig:
allowedUsers: |
# set new field not exposed in helm chart < 0.10.6
set_config_if_not_none(c.Authenticator, "allowed_users", "auth.allowedUsers")For more information
If you have any questions or comments about this advisory:
- Open a thread on the Jupyter forum
- Email us at security@ipython.org
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | oauthenticator | >= 0.12.0, < 0.12.2 | 0.12.2 |
References
- https://github.com/jupyterhub/oauthenticator/blob/master/docs/source/changelog.md#0122---2020-11-30
- https://github.com/jupyterhub/oauthenticator/commit/a4aac191c16cf6281f3d346615aefa75702b02d7
- https://jupyterhub.readthedocs.io/en/1.2.2/getting-started/authenticators-users-basics.html#add-or-remove-users-from-the-hub
- https://github.com/jupyterhub/oauthenticator/security/advisories/GHSA-384w-5v3f-q499
- https://nvd.nist.gov/vuln/detail/CVE-2020-26250
- https://github.com/jupyterhub/oauthenticator
- https://github.com/pypa/advisory-database/tree/main/vulns/oauthenticator/PYSEC-2020-68.yaml
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N- Weakness (CWE)
CWE-863- Platform
- Python (PyPI)
- Package
oauthenticator- Disclosed
- 01.12.2020
- Updated
- 11.10.2026 13:19
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2020-68 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-384w-5v3f-q499 - CC BY 4.0
Vulnerability history: oauthenticator
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 6
- First → latest
- 02.2018 04.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 5
- Medium 1
Disclosures per year
- 2018: 1
- 2019: 0
- 2020: 1
- 2021: 0
- 2022: 1
- 2023: 0
- 2024: 2
- 2025: 0
- 2026: 1
-
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