SB2021110429 - Insufficient Session Expiration in jupyterhub
Published: November 4, 2021 Updated: April 28, 2026
Security Bulletin ID
SB2021110429
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Insufficient Session Expiration (CVE-ID: CVE-2021-41247)
The vulnerability allows a remote user to regain access to the single-user server after logout.
The vulnerability exists due to insufficient session expiration in the JupyterHub single-user server session handling when logging out with another active JupyterLab session open in the same browser session. A remote user can keep multiple JupyterLab tabs open and log out in one tab to regain access to the single-user server after logout.
The issue affects fresh credentials for the single-user server only, not the Hub.
Remediation
Install update from vendor's website.