incomplete JupyterHub logout with simultaneous JupyterLab sessions
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 software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | jupyterhub | >= 1.0.0, < 1.5.0 | 1.5.0 |
References
- https://github.com/jupyterhub/jupyterhub/security/advisories/GHSA-cw7p-q79f-m2v7
- https://github.com/jupyterhub/jupyterhub/commit/5ac9e7f73a6e1020ffddc40321fc53336829fe27
- https://nvd.nist.gov/vuln/detail/CVE-2021-41247
- https://github.com/jupyterhub/jupyterhub
- https://github.com/pypa/advisory-database/tree/main/vulns/jupyterhub/PYSEC-2021-386.yaml
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N- Weakness (CWE)
CWE-613- Platform
- Python (PyPI)
- Package
jupyterhub- Disclosed
- 04.11.2021
- Updated
- 11.10.2026 13:19
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2021-386 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-cw7p-q79f-m2v7 - CC BY 4.0
Vulnerability history: jupyterhub
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
- 8
- First → latest
- 04.2019 08.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 2
- Medium 6
Disclosures per year
- 2019: 1
- 2020: 0
- 2021: 2
- 2022: 0
- 2023: 0
- 2024: 2
- 2025: 0
- 2026: 3
-
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