Open redirect in jupyterlab jupyter_server
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Spoofing
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-601.
Summary
The Jupyter Server provides the backend (i.e. the core services, APIs, and REST endpoints) for Jupyter web applications like Jupyter notebook, JupyterLab, and Voila. In Jupyter Server before version 1.1.1, an open redirect vulnerability could cause the jupyter server to redirect the browser to a different malicious website. All jupyter servers running without a base_url prefix are technically affected, however, these maliciously crafted links can only be reasonably made for known jupyter server hosts. A link to your jupyter server may *appear* safe, but ultimately redirect to a spoofed server on the public internet. This same vulnerability was patched in upstream notebook v5.7.8. This is fixed in jupyter_server 1.1.1. If upgrade is not available, a workaround can be to run your server on a url prefix: "jupyter server --ServerApp.base_url=/jupyter/".
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| jupyterlab | jupyter_server | before 1.1.1 | 1.1.1 | Patch available | CNA |
| — | jupyter-server (PyPI) | before 1.1.1 | 1.1.1 | Patch available | GHSA-9f66-54xg-pc2c |
- jupyter_server Vendorjupyterlab Affected before 1.1.1 Fixed in 1.1.1 Patch available CNA
- jupyter-server (PyPI) Vendor— Affected before 1.1.1 Fixed in 1.1.1 Patch available GHSA-9f66-54xg-pc2c
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:jupyter:jupyter_server:*:*:*:*:*:*:*:* | before 1.1.1 | Vulnerable | jupyterlab |
- cpe:2.3:a:jupyter:jupyter_server:*:*:*:*:*:*:*:* Versions before 1.1.1 Vulnerable ·jupyterlab
Remediation
- Fix · CNA jupyter_server (jupyter-server) Fixed in 1.1.1
- Fix · GHSA-9f66-54xg-pc2c jupyter-server (PyPI) Fixed in 1.1.1 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2020-26275
- 2026-10-03 Alias added: GHSA-9f66-54xg-pc2c
References
Patch 2
Other 5
- https://pypi.org/project/jupyter-server/
- https://github.com/jupyter-server/jupyter_server
- https://github.com/pypa/advisory-database/tree/main/vulns/jupyter-server/PYSEC-2020-346.yaml
- https://github.com/pypa/advisory-database/tree/main/vulns/jupyter-server/PYSEC-2020-50.yaml
- https://pypi.org/project/jupyter-server
More jupyterlab Jupyter Server vulnerabilities
- TI-2026-05842 CORS Origin Validation Bypass in jupyter-server CVSS 3.1HIGH 8.8
- TI-2026-04748 Path Traversal in jupyter/jupyter CVSS 3.1HIGH 8.1
- TI-2026-27533 jupyter-server path traversal allows access to sibling directories sharing root_dir name prefix CVSS 4.0HIGH 7.6
- TI-2025-38102 jupyter_server next parameter open redirect can redirect users to external domains CVSS 4.0MEDIUM 6.3
- TI-2026-32614 Jupyter Server: Stored XSS in `NbconvertFileHandler` / `NbconvertPostHandler` via missing `sandbox` CSP CVSS 4.0CRITICAL 9.3
- TI-2024-23252 Jupyter server on Windows discloses Windows user password hash CVSS 3.1HIGH 7.5
Sources
- CVE-2020-26275 · CVE Program
- CVE-2020-26275 · NVD
- FIRST EPSS
- GHSA-9f66-54xg-pc2c · GitHub Advisory Database · CC BY 4.0
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