AI and data stack advisories

Severe, 6 weeks1496Projects326

1496 severe, 6 weeks · 326 projects

JupyterGHSA-cw7p-q79f-m2v7

incomplete JupyterHub logout with simultaneous JupyterLab sessions

Jupyter

CVE-2021-41247 · Published Nov 8, 2021 · updated Jul 8, 2026

Medium3.5
Fix: upgrade to 1.5.0 or later
GitHub advisory

Impact

Users of JupyterLab with JupyterHub who have multiple JupyterLab tabs open in the same browser session, may see incomplete logout from the single-user server, as fresh credentials (for the single-user server only, not the Hub) reinstated after logout, if another active JupyterLab session is open while the logout takes place.

Patches

Upgrade to JupyterHub 1.5. For distributed deployments, it is jupyterhub in the _user_ environment that needs patching. There are no patches necessary in the Hub environment.

Workarounds

The only workaround is to make sure that only one JupyterLab tab is open when you log out.

Affected versions

PackageAffectedFixed in
jupyterhub
PyPI
>= 1.0.0, < 1.5.01.5.0
Details and references

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