CVE-2025-61669
Severity CVSS v4.0:
MEDIUM
Type:
CWE-601
URL Redirection to Untrusted Site ('Open Redirect')
Publication date:
05/05/2026
Last modified:
05/05/2026
Description
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.
Impact
Base Score 4.0
6.30
Severity 4.0
MEDIUM



