CVE-2021-41247: low-severity vulnerability in jupyterhub
incomplete logout in JupyterHub
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
8Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 3.5epss 0.8%
JupyterHub is an open source multi-user server for Jupyter notebooks. In affected versions users 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. 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. The only workaround is to make sure that only one JupyterLab tab is open when you log out.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
Affected products
jupyterhub · jupyterhubRelated CVEs — jupyterhub
In the same product, most dangerous first.
CVE-2024-41942HIGHJupyterHub has a privilege escalation vulnerability with the `admin:users` scopeEPSS 0.6%CVE-2026-54338MEDIUMJupyterHub: Unauthenticated Denial of Service via Unbounded Username Logging on Failed LoginEPSS 0.4%CVE-2024-28233HIGHXSS in JupyterHub via Self-XSS leveraged by Cookie TossingEPSS 0.3%CVE-2026-108752LOWJupyterHub through 6.0.1 OAuth Client ID Collision via Unescaped HyphenEPSS 0.2%CVE-2026-33709MEDIUMJupyterHub has an Open Redirect VulnerabilityEPSS 0.2%CVE-2026-40864MEDIUMJupyterHub: Cross-origin form POSTs bypass XSRFEPSS 0.1%