PatchTheCVECVE-2025-61669: Jupyter Server is the backend for Jupyter web applications
CVE-2025-61669 is a medium-severity flaw (CVSS 6.1) affecting jupyter server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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
Why this priority
- Public exploit reference
A fixed release or distro patch exists.
Risk facts
| CVSS score | 6.1 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | Required |
| EPSS exploit chance | 0.2% (top 85%) |
| CISA exploited list | No |
| Weakness | CWE-601 |
| Published | 2026-05-05 |
| Last modified | 2026-10-07 |
Last updated 2026-10-07 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2025-61669?
jupyter server: upgrade to 2.18.0. Exact commands for each OS are on this page.
Is CVE-2025-61669 being exploited?
CVE-2025-61669 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2025-61669 affect?
CVE-2025-61669 affects jupyter server. Severity is medium (CVSS 6.1). 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
How urgent is CVE-2025-61669?
Priority 30/100. Public exploit reference
Software pages
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- CVE-2026-5422 HIGH 8.1 DOWNGRADE A path traversal vulnerability exists in jupyter-server version 2.17.0 due to an incorrect root directory boun