CVE-2025-61669
Published:May 05, 2026
Updated:May 14, 2026
Jupyter Server is the backend for Jupyter web applications. In jupyter_server versions through 2.17.0, the next query parameter in the login flow is insufficiently validated in "LoginFormHandler._redirect_safe()", which allows redirects to arbitrary external domains via values such as "///example.com". An attacker can use a crafted login URL to redirect users to a malicious site and facilitate phishing attacks. This issue is fixed in version 2.18.0.
Affected Packages
jupyter_server (CONDA):
Affected version(s) >=0.0.2 <2.18.0Fix Suggestion:
Update to version 2.18.0https://github.com/jupyter-server/jupyter_server.git (GITHUB):
Affected version(s) >=v1.6.2 <v2.18.0Fix Suggestion:
Update to version v2.18.0jupyter_server (PYTHON):
Affected version(s) >=0.0.0 <2.18.0Fix Suggestion:
Update to version 2.18.0jupyter-server (PYTHON):
Affected version(s) >=0.0.0 <2.18.0Fix Suggestion:
Update to version 2.18.0Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
6.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
HIGH
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.4
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
URL Redirection to Untrusted Site ('Open Redirect')
EPSS
Base Score:
0.01