CVE-2025-61669
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.
- CVSS 4.0
- 6.3
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 - CVSS 3.1
- 6.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 15% of CVEs (scores of 2026-10-25)
- CWE
- CWE-601
- Published
- Modified
- Record from
- the NVD, synced
Affected
- jupyter:jupyter_server
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-qh7q-6qm3-653w | PyPI | jupyter-server | <2.18.0 | 2.18.0 |
| PYSEC-2026-67 | PyPI | jupyter-server | <2.18.0 | 2.18.0 |