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.
History

Mon, 11 May 2026 15:15:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:jupyter:jupyter_server:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}


Tue, 05 May 2026 21:45:00 +0000

Type Values Removed Values Added
First Time appeared Jupyter
Jupyter jupyter Server
Vendors & Products Jupyter
Jupyter jupyter Server

Tue, 05 May 2026 21:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 05 May 2026 16:15:00 +0000

Type Values Removed Values Added
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.
Title jupyter_server next parameter open redirect can redirect users to external domains
Weaknesses CWE-601
References
Metrics cvssV4_0

{'score': 6.3, '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-05T20:16:59.332Z

Reserved: 2025-09-29T20:25:16.180Z

Link: CVE-2025-61669

cve-icon Vulnrichment

Updated: 2026-05-05T20:16:10.899Z

cve-icon NVD

Status : Analyzed

Published: 2026-05-05T16:16:10.133

Modified: 2026-05-11T13:01:45.537

Link: CVE-2025-61669

cve-icon Redhat

No data.