CVE-2025-61669 MEDIUM

CVE-2025-61669: jupyter_server next parameter open redirect can redirect users to external domains

Vendor Jupyter-Server
Product jupyter_server
Weakness CWE-601 · Open redirect
Published May 5, 2026
Last update May 5, 2026
View on NVD All CVEs

CVSS base score

6.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction —
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

May 5, 2026 CVE published
May 5, 2026 Record updated