CVE-2025-61669

jupyter_server next parameter open redirect can redirect users to external domains

Published May 5, 2026 CVSS 4.0 · 6.3 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-qh7q-6qm3-653w Jupyter Server has an open redirection vulnerability in `next` query parameter
History
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'}

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

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

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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
May 5, 2026, 8:16 PM
Reserved
Sep 29, 2025, 8:25 PM
Status
Analyzed
Published
May 5, 2026, 4:16 PM
Modified
Oct 7, 2026, 9:10 AM
Severity
Moderate
Public date
May 5, 2026, 3:28 PM