Insufficient Session Expiration in Jupyter Server - CVE-2026-40934
Published: May 5, 2026
Vulnerability identifier: #VU130162
CSH Severity: Low
CVSS v4: 7.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-40934
CWE-ID: CWE-613
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to maintain indefinite authenticated access.
The vulnerability exists due to insufficient session expiration in the authentication cookie handling when reusing previously issued authentication cookies after a password reset and server restart. A remote user can reuse a stolen or compromised authentication cookie to maintain indefinite authenticated access.
The issue affects deployments using password authentication.
Affected software
Jupyter Server
openEuler
python-jupyter-server
python3-jupyter-server
openEuler
python-jupyter-server
python3-jupyter-server
How to mitigate CVE-2026-40934
Install security update from vendor's website.
Jupyter Server - update to 2.18.0
python-jupyter-server - addressed in versions 2.13.0-3, 2.13.0-4
python3-jupyter-server - addressed in versions 2.13.0-3, 2.13.0-4
python-jupyter-server - addressed in versions 2.13.0-3, 2.13.0-4
python3-jupyter-server - addressed in versions 2.13.0-3, 2.13.0-4